LIBRARY 

OF  THE 

UNIVERSITY  OF  CALIFORNIA. 


Class 


Water-Works  Management 
and  Maintenance 


BY 
WINFRED    D.    HUBBARD 

Assoc.  M.  Am.  Soc.  C.  E. 
AND 

WYNKOOP    KIERSTED 

M.  Am.  Soc.  C.  E.,  Consulting  Engineer 


FIRST   EDITION 
FIRST  THOUSAND 


JOHN    WILEY     &    SONS 

LONDON:    CHAPMAN   &   HALL,     LIMITED 

1907 


COPYRIGHT,  1907 

BY 
WINFRED  D.  HUBBARD 

AND 

WYNKOOP  KIERSTED 


ROBERT  DRUMMOND  COMPANY,  PRINTERS,  NEW  YORK 


INTRODUCTION. 


THE  maintenance  and  operation  of  a  system  of  water-works  is 
often  believed  to  be  a  purely  business  proposition  requiring  essentially 
a  business  management.  Regarded  in  a  broad  and  comprehensive 
sense  this  view  may  be  correct,  for  a  far-seeing  business  management 
would  not  overlook  the  purely  technical  or  scientific  considerations 
which  are  necessarily  involved  in  the  management  of  a  modern  water- 
works system.  The  questions  involved  do  not  relate  solely  to  the 
sale  of  a  commodity  supplied  in  the  form  of  a  water  service,  but  also 
deal  with  the  quality  of  the  water  supplied  and  the  design,  con- 
struction, and  operation  of  the  physical  property  by  and  through 
which  the  service  is  rendered. 

The  selection  of  a  water-supply  drawn  from  an  unpolluted  source 
is  highly  desirable  and  inspires  the  confidence  of  the  public  in  the 
management  of  water-works.  This  confidence,  however,  may  be 
also  secured  when  circumstances  compel  the  use  of  a  water  drawn 
from  polluted  sources,  provided  the  water  be  properly  purified 
before  use.  Many  natural  waters  contain  more  or  less  dissolved 
minerals,  such  as  lime,  magnesia,  and  iron,  which  are  of  themselves 
harmless,  although  in  some  instances  objectionable  when  the  water 
is  required  for  some  particular  mechanical  purpose.  A  soft  water  is 
always  to  be  preferred  for  general  use  and  is  usually  obtained  from 
some  surface  source  when  a  desirable  selection  can  be  made;  but 
a  moderately  hard  water  is  sometimes  accepted  for  a  public  supply 
rather  than  incur  the  expense  of  the  construction  and  operation 
of  purification  works.  Turbidity  and  color,  whether  due  to  sedi- 
ment mechanically  suspended  in  water  or  to  vegetable  stain,  are 
offensive  even  when  present  in  a  moderate  degree,  although  they 
may  not  render  the  water  unwholesome.  The  introduction  of 
pathogenic  bacteria  into  a  water-supply  by  contamination  by  sewage 
or  other  wastes  is  often  productive  of  disease,  and  the  human  system 

iii 

161547 


IV  INTRODUCTION. 

may  be  readily  infected  through  the  medium  of  drinking-water 
exposed  to  pollution  of  this  nature.  In  consequence,  sanitarians  at 
the  present  time  regard  the  quality  of  a  water  for  hygienic  purposes 
as  closely  associated  with  the  bacterial  life  which  it  may  contain. 

Taking  into  consideration  the  many  things  which  have  to  be 
regarded  in  the  selection  and  purification  of  water-supplies,  it  is 
clear  that  science  can  be  serviceable  to  a  water-works  management 
in  many  ways,  and  the  advantage  of  this  kind  of  service  should 
become  more  and  more  apparent  as  communities  increase  and 
prosper.  If  the  aid  of  science  is  necessary  to  select  a  source  of  sup- 
ply free  from  dangerous  pollution  or  to  detect  the  presence  of  unob- 
served polluting  influences,  its  aid  is  even  more  necessary  in  those 
cases  where  a  source  of  supply,  known  to  be  polluted,  requires 
thorough  purification.  It  will  not  suffice  to  seek  scientific  assist- 
ance in  such  a  case  solely  for  the  purpose  of  designing  and 
constructing  purification  works,  but  it  should  also  be  retained  for 
the  purpose  of  insuring  the  satisfactory  operation  of  these  works 
and  the  preservation  of  the  purity  of  the  water  after  treatment. 
The  safeguards  of  the  public  health  in  the  way  of  constructed 
works  need  guardsmen  to  see  that  such  works  positively  perform 
the  functions  expected  of  them  at  all  times — a  service  which  may 
yet  have  to  be  supplied  through  the  State  or  Federal  government. 

From  the  foregoing  it  will  appear  that  questions  relating  to  the 
maintenance  and  operation  of  a  system  of  water- works  often  depend 
for  their  proper  solution  upon  the  details  of  the  original  design,  and 
the  authors  have  deemed  it  advisable  to  outline  to  some  extent  in 
Part  I  the  various  methods  by  which  a  supply  is  secured. 

Part  II  deals  particularly  with  matters  more  closely  connected 
with  the  ordinary  routine  management  of  a  water-works  plant. 

In  Part  III  consideration  is  given  to  questions  which  arise  in  the 
dealings  of  municipalities  with  private  water  companies.  These 
questions  have  been  brought  to  the  attention  of  communities  to  a 
large  extent  during  recent  years  by  the  trend  toward  municipal 
ownership  of  public  utilities,  and  the  principles  involved  in  the  fix- 
ing of  water  rates  and  the  valuation  of  water-works  property  are 
presented  in  detail. 


CONTENTS. 


'  PART   I. 

ON  THE  METHODS  AND  PRINCIPLES  OF  DEVELOPING, 
IMPROVING,    AND   STORING   WATER-SUPPLIES. 

CHAPTER    I.     (w.  K.) 

PAGE 

GROUND-WATER  SUPPLY i 

CHAPTER    II.     (w.  K.) 
RIVER-WATER  SUPPLY 116 

CHAPTER    III.     (w.  K.) 

PUMPING-ENGINES 183 

CHAPTER       IV.       (W.   D.   H.) 

IMPOUNDED  SUPPLIES 204 


PART   II. 

MAINTENANCE   AND   OPERATION. 

CHAPTER   I.     (w.  D.  H.) 
PLANS  AND  RECORDS 218 

CHAPTER   II.     (w.  D.  H.) 
EXTENSIONS 232 

CHAPTER   III.     (w.  D.  H.) 
SERVICE  CONNECTIONS 249 

CHAPTER    IV.     (w.  D.  H.) 

METERS 265 

v 


vi  CONTENTS. 


CHAPTER   V.     (w.  D.  H.) 

PAOH 

CARE  OF  APPURTENANCES 280 

CHAPTER    VI.     (w.  D.  H.) 
ALTERATIONS  AND  REPAIRS 298 

CHAPTER   VII.      (w.  D.  H.) 
MAINTENANCE  OF  QUALITY   311 

CHAPTER   VIII.     (w.  D.  H.) 
WATER  WASTE      324 

CHAPTER    IX.      (w.  D.  H.) 
ELECTROLYSIS 343 

CHAPTER      X.      (w.  D.  H.) 
FIRE  PROTECTION 352 

CHAPTER   XI.      (w.  D.  H.) 
ACCOUNTS 36 1 

CHAPTER   XII.     (w.  D.  H.) 
FINANCIAL  MANAGEMENT 366 

CHAPTER   XIII.     (w.  D.  H.) 
RULES  AND  REGULATIONS 377 

CHAPTER    XIV.     (w.  D.  H.) 
ANNUAL  REPORTS 380 


PART   III.     (w.  K.) 
FRANCHISE.     WATER  RATES.     DEPRECIATION....   385 


Of  THE 

UNIVERSITY 

OF 


WATER-WORKS    MANAGEMENT 
AND    MAINTENANCE. 


PART  I. 

ON    THE   METHODS    AND    PRINCIPLES    OF 
DEVELOPING,  IMPROVING,  AND  STOR- 
ING WATER-SUPPLIES. 


CHAPTER  I. 

GROUND-WATER  SUPPLY. 

Quality. — There  is  a  charm  and  satisfaction  attached  to  the 
cool,  sparkling,  and  refreshing  draught  from  a  natural  spring 
which  incites  a  warm  and  enduring  friendship  for  it.  The  perfect 
transparency  of  the  water  and  its  comforting  and  refreshing  effect 
offer  no  hint  that  between  the  sparkling  spring  and  its  origin, 
the  rainfall,  the  water  possesses  a  long  and  obscure  history.  Per- 
haps the  very  obscurity  of  the  precise  nature  of  this  history  gives 
substance  to  the  water's  enchanting  influence.  But  hidden  as  it 
is  and  with  no  visible  signs  that  that  history  could  have  been  any- 
thing but  good  in  its  long  and  untraceable  source  through  the 
ground,  there  is  apparent  to  the  observer  no  tangible  ground 
upon  which  to  base  the  slightest  suspicion  of  its  purity  so  long 
as  it  is  agreeable  both  to  taste  and  sight.  We  therefore  detect  in 
ground-water  the  nearest  approach  to  what  may  be  popularly 
considered  an  ideal  drinking-water.  In  fact  we  find  it  above 
suspicion  and  reproach  in  rural  districts,  almost  invariably  of 
first  consideration  in  communities  desiring  to  acquire  a  public 


2  WATER-SUPPLIES. 

water-supply,  and  often  regarded  technically  as  of  the  highest 
rank  among  the  various  sources  of  water-supply. 

Sentiment  and  advertisement  may  stimulate  a  regard  for  a 
water  of  certain  springs  above  that  of  other  springs  because  the 
reputation  thus  gained  usually  centers  around  some  medicinal 
qualities  the  water  of  such  springs  is  supposed  to  possess.  These 
special  waters,  the  qualities  of  which  are  developed  and  sought 
out  for  special  reasons  and  for  special  purposes,  are  not  classed 
with  the  ordinary  run  of  ground-waters  available  for  the  public 
water-supply. 

The  basis  of  popular  acceptance  of  a  ground-water  is  usually 
its  appearance  and  general  palatability,  and  as  a  rule  its  appear- 
ance neither  presents  nor  suggests  evidence  of  present  or  past 
pollution.  However,  a  little  reflection  must  tell  us  that  the  rain- 
fall which  washes  the  air  and  the  surface  of  the  ground  must  come 
in  contact  with  contaminating  influences  to  a  greater  or  less  degree, 
particularly  in  populous  districts.  Just  how  far  we  may  encroach 
upon  the  domain  of  nature  with  our  modern  civilization  and 
multiply  instances  of  contamination  upon  her  fair  face  without 
seriously  polluting  the  rainfall,  the  source  of  all  ground-water 
supply,  is  a  question  with  which  the  water  analyst  and  specialist 
is  engaged.  The  further  these  investigations  proceed  along  ra- 
tional lines  the  cruder  appear  the  past  methods  and  means  of  de- 
termining and  judging  of  the  wholesomeness  of  a  ground- water 
and  the  more  secure  appear  the  provisions  of  nature  to  remove 
the  impurities  collected  by  the  rainfall  even  in  populous  districts. 
In  fact  it  is  exceedingly  doubtful  that  we  yet  realize  and  fully 
appreciate  the  true  character,  scope,  and  security  of  these  pro- 
visions of  nature.  While  some  forms  of  bacterial  life  may  be  a 
source  of  danger  in  water,  it  is  well  known  that  bacterial  life  of 
other  forms  is  a  source  of  security.  For  instance  the  portion  of  the 
rainfall  which  enters  the  ground,  even  though  it  may  be  grossly 
polluted  by  surface  contact  with  decaying  matter,  is  quickly 
relieved  of  its  dissolved  organic  impurities  by  the  bacterial  life 
which  infests  the  surface  soils  and  thrives  upon  the  food  which 
percolating  water  conveys  to  it.  The  ideal  geological  condition 
for  the  natural  purification  of  water  is  to  be  found  in  a  plane  of 
well-ventilated  sandy  soil  upon  which  the  rainfall  remains  quite 


GROUKD-WATER  SUPPLY.  3 

uniformly  distributed  until:  absorbed.  A  slow  percolation  through 
a  comparatively  few  feet  of  such  soil  is  sufficient  for  the  purification 
of  the  rainfall.  It  is  believed  that  pathogenic  germs  which  water 
may  have  absorbed  at  the  surface  of  the  ground  cannot  survive  a 
slow  passage  through  such  soil  teeming  with  natural  but  to  them 
antagonistic  bacterial  life.  There  is  every  reason  to  believe  that  a 
ground-water  will  be  found  quite  as  pure  a  comparatively  few  feet 
below  the  surface  of  a  sandy  soil  as  many  feet  below  it,  provided 
there  are  no  more  direct  lines  of  communication  than  those 
through  the  voids  of  the  sand. 

Sanitary  analysis  of  a  ground-water  tells  of  the  existing  con- 
dition of  the  water  as  exemplified  by  the  samples  analyzed, 
of  the  probable  present  and  past  relation  of  the  water  with  putres- 
cible  organic  matter,  and  of  the  possible  contamination  of  the 
water  from  sources  which  cannot  be  detected  by  a  personal  inspec- 
tion of  the  territory  receiving  the  rainfall.  It  is  indicative  of  the 
degree  to  which  the  process  of  natural  purification  has  progressed. 
It  deals  with  existing  facts  and  conditions,  and  when  regularly 
made  affords  direct  evidence  of  changes  in  the  characteristics  of 
a  water  as  they  occur.  It  can  give  little  reliable  information  of  a 
danger  threatening  eventually  to  become  a  source  of  contamination. 

A  sanitary  chemical  analysis  of  a  shallow  ground-water  con- 
cerns itself  most  with  the  existing  state  of  the  organic  matter 
dissolved  in  the  water  analyzed,  with  the  hardness  of  the  water, 
and  with  the  amount  and  condition  of  iron  the  water  may  con- 
tain, and  with  the  total  solids  in  solution. 

The  term  albuminoid  ammonia  used  in  recording  the  results 
of  a  chemical  analysis  indicates  the  undecomposed  organic  matter 
remaining  in  a  water,  the  terms  free  ammonia  and  nitrites  are 
considered  respectively  measures  of  progressive  decomposition  of 
organic  matter,  and  the  term  nitrates  represents  the  final  result  of 
decomposition  when  the  decomposed  elements  of  the  organic 
matter  have  united  with  some  mineral  in  the  water.  The  trans- 
formation in  its  completeness  is  from  putrescible  organic  matter 
to  a  stable  mineral  compound.  A  water  which  possesses  evidence 
of  all  the  intermediate  steps  in  this  transformation  is  considered 
imperfectly  purified  and  may  be  still  subject  to  the  agencies  pro- 
ducing the  change.  The  presence  of  albuminoid  and  free  ammonias 


4  WATER-SUPPLIES. 

in  small  quantities  or  in  a  stable  condition,  the  absence  of  nitrites, 
and  the  presence  of  the  nitrates  in  either  large  or  small  amounts 
afford  evidence  of  complete  purification. 

Chlorine,  usually  present  as  common  salt,  has  no  direct  chemical 
connection  with  the  organic  matter  in  water,  is  unchangeable  and 
harmless,  and  is  often  regarded  as  an  evidence  of  sewage  pollution 
when  the  amount  in  the  water  exceeds  that  derived  from  natural 
sources. 

A  few  years  ago,  before  biology  demonstrated  bacteria  in  some 
form  to  be  the  active  agents  of  water  purification  and  the  real 
element  to  be  feared  in  a  polluted  water,  the  result  of  a  chemical 
analysis  showing  abnormal  amounts  of  chlorine  and  nitrates  would 
have  been  considered  sufficient  evidence  of  impurity  to  condemn 
the  water  because  of  past  association  with  organic  impurity.  This 
conclusion  was  based  upon  the  consideration  that  suspicion  should 
attach  to  a  water  showing  evidence  of  past  pollution  because  of  a 
fear  that  the  conditions  of  complete  natural  purification  may  not 
remain  perfect,  rather  than  upon  a  consideration  of  danger  in  the 
presence  of  the  compounds  themselves.  At  the  present  time  the 
conditions  surrounding  the  natural  filtration  of  ground-water  are 
better  understood,  and  better  understanding  inspires  greater  con- 
fidence in  the  process  of  natural  purification  and  offers  a  stronger 
assurance  of  the  certainty  with  which  this  operation  of  nature  is 
conducted  even  when  water  is  exposed  to  much  more  pollution 
than  that  naturally  encountered. 

We  are  thus  unable  to  draw  rigidly  the  line  of  demarcation 
between  a  wholesome  and  an  unwholesome  water  in  so  far  as  the 
quality  of  the  water  is  revealed  to  us  through  the  application  of 
the  science  of  chemistry  alone.  A  knowledge  of  the  physical  char- 
acteristics of  the  territory  from  which  the  ground-water  is  supplied 
is  often  a  more  reliable  guide  than  is  the  result  of  a  chemical  analy- 
sis alone.  But  both  sources  of  information  when  fully  developed 
should  ba  mutually  supporting. 

The  importance  of  the  application  of  the  science  of  bacteriology 
to  the  study  of  water-supply  arises  from  the  fact  that  drinking-water 
is  a  medium  through  which  the  bacilli  of  certain  diseases  may  be 
imbibed  and  infection  widely  disseminated  when  the  water  is  ex- 
posed to  the  pollution  of  infectious  bacterial  life  without  inter- 


GROUND-WATER  SUPPLY.  5 

mediate  provision  for  its  destruction  or  removal.  The  most  prob- 
able source  of  disease  germs  in  water  is  direct  sewage  contamina- 
tion, and  therefore  the  bacteriologist  searches  for  bacterial  life 
characteristic  of  that  known  to  exist  in  sewage  in  abundance. 
The  presence  in  the  water  of  sewage  bacteria  renders  a  water  open 
to  suspicion;  the  absence  of  this  form  of  life  allays  suspicion  even 
though  the  water  may  contain  in  small  degree  harmless  forms  of 
bacterial  life  native  to  water. 

Attention  is  called  to  the  following  analysis  to  illustrate  the' 
effect  which  exposure  of  the  rainfall  to  polluting  matter  upon  the 
surface  of  the  ground  may  have  upon  ground-water  derived  from 
springs  and  shallow  wells. 

(In  parts  per  million.) 


Wei 
If* 

J  300  feet  from 
ssissippi  River. 

264.00 

O.OI 

0.014 
None 
9-6 
0.6 
6.8 

Mississippi 
River  water. 

329.00 
0-34 
0-394 

0.02 

I  .  7C 

Spring 
Brook. 

126  .0 
Trace 
0.028 
None 
0.028 

1C.  •* 

Free  ammonia  

Albuminoid  ammonia.  .  .  . 
Nitrites  

Nitrates                   

Oxygen  consumed 

Chlorine.  . 

The  analysis  of  the  water  of  the  well  near  the  Mississippi  River 
indicates  past  pollution  of  a  considerable  amount  but  thorough 
subsequent  purification.  The  bacteria  in  the  well  were  few, 
numbering  20  to  40  per  cubic  centimeter  and  of  a  harmless  variety. 
The  water  is  also  noteworthy  in  the  regard  that  the  sample,  though 
taken  about  50  feet  below  the  surface  of  the  ground,  contains  less 
dissolved  minerals  than  the  water  of  the  adjoining  river.  The  catch- 
ment area  supplying  the  well  from  which  the  sample  of  water 
analyzed  was  taken  is  a  sandy  plane  extensively  cultivated  and 
heavily  fertilized.  Doubtless  the  origin  of  the  nitrogen  and 
abnormal  chlorine  in  the  well-water  is  the  fertilizer  which  is  used 
upon  the  surface  of  the  ground. 

The  sample  of  water  from  the  spring  brook  was  taken  near  a 
spring  which  is  supplied  by  rainfall  upon  a  timbered,  sandy,,  un- 
cultivated catchment  area.  The  analysis  shows  a  small  amount  of 
organic  pollution  and  accordingly  is  greatly  in  contrast  with  that 
of  the  sample  supplied  from  the  cultivated  catchment  area  de- 
scribed in  the  preceding  paragraph. 


6  WATER-SUPPLIES. 

However,  the  character  of  the  water  from  both  the  well  and 
the  spring  brook  could  be  substantially  forecasted  by  survey  of 
the  physical  characteristics  of  the  respective  catchment  areas. 
Both  waters  were  finally  pronounced  wholesome. 

Careful  survey  of  the  physical  characteristics  of  a  catchment 
area  feeding  comparatively  shallow  water  bearing  sand  and  gravel 
beds  taken  in  connection  with  the  information  furnished  by  chem- 
ical and  bacterial  analysis  of  the  water  itself  constitutes  a  com- 
prehensive sanitary  survey,  and  when  the  results  of  the  several 
examinations  and  analyses  are  interpreted  with  due  mutual  re- 
gard, we  may  reach  substantially  correct  and  safe  conclusion  as 
to  the  wholesomeness  of  a  ground-water.  A  purely  independent 
interpretation  of  the  results  of  any  one  of  the  three  elements  re- 
ferred to  may  lead  to  a  wrong  conclusion;  for  instance  the  results 
of  the  analysis  of  the  well-water  given  in  the  preceding  table,  if 
interpreted  from  a  chemical  point  of  view  alone  in  accordance 
with  the  so-called  standard  of  purity  of  a  potable  water  as  laid 
down  in  some  of  the  older  books  on  water-supply,  would  certainly 
lead  to  a  rejection  of  that  water,  although  in  fact  the  pollution 
indicated  is  purely  a  matter  of  the  past  state  of  the  water.  Simi- 
larly a  purely  physical  examination  may  discover  sources  of  pollu- 
tion for  the  rainfall  of  such  a  character  and  so  located  as  to  arouse 
a  suspicion  that  the  polluting  influence  may  extend  to  the  sub- 
terranean waters  and  accordingly  seek  the  assistance  of  both  a 
chemical  and  bacteriological  examination  of  the  underground 
waters  to  either  remove  or  confirm  the  suspicion. 

In  a  general  way  it  may  be  stated  that  polluting  matter  upon 
the  surface  of  the  ground  cannot  be  carried  by  absorbed  rainfall 
into  the  underground  water  by  percolating  through  intervening 
soil  without  purification.  The  danger  of  pollution  of  this  sort 
lies  in  a  direct  communication  between  the  surface  and  the  under- 
ground waters,  as,  for  instance,  when  surface-water  overflows  or 
passes  through  the  curb  of  an  open  well  or  well-developed  fissure 
channels. 

Polluting  matter,  particularly  excrement  deposited  in  covered 
excavations  like  the  ordinary  privy,  is  less  exposed  to  natural 
purifying  influences  than  similar  matter  upon  the  surface  of  the 
ground  and  accordingly  is  more  to  be  feared,  but  the  con t ami- 


GROUND-WATER  SUPPLY.  ^ 

nating  effect  of  such  matter  so  deposited  is  confined  to  a  much 
more  restricted  area  than  many  people  would  suppose  when  the 
excrement  rests  on  the  subsoil.  However,  if  the  excrement  rest 
upon  fissured  rock  exposed  by  the  excavation  of  the  privy,  the 
connection  between  the  receptacle  and  underground  water  may 
be  direct  and  pollution  proportionally  extended. 


Water  from  deep  wells  possesses  entirely  different  character- 
istics and  cannot  be  regarded  in  the  same  category  as  shallow-well 
water.  Usually  such  wells  penetrate  rock  or  alternate  layers  of 
porous  and  impervious  materials  and  are  supplied  by  the  rainfall 
on  remote  catchment  areas.  As  a  rule  the  water  from  such  wells 
is  practically  sterilized  by  a  prolonged  and  slow  process  of  filtra- 
tion. A  visual  survey  can  scarcely  be  made  of  the  catchment  area 
except  where  the  geological  structure  of  the  surrounding  territory 
is  known  by  extended  surveys,  and  a  bacterial  analysis  of  the 
water  is  scarcely  necessary  because  prolonged  filtration  deprives 
the  water  of  bacterial  life.  A  chemical  examination  is  practi- 
cally all  that  is  needed,  and  this  chiefly  to  determine  the  amount 
and  character  of  dissolved  mineral  matter. 

With  regard  to  water  of  this  class  the  subject  can  be  concisely 
covered  by  quoting  from  the  reports  made  in  connection  with  the 
water-supply  of  Galveston,  Texas: 

"GALVESTON,  TEXAS,  November  ipth,  1892. 

"To  the  Honorable  Board  of  Commissioners  of  Water-works,  Gal- 
veston, Texas. 

"Gentlemen:  The  following  report  is  submitted,  mainly  from 
a  sanitary  standpoint,  with  respect  to  the  new  water-supply  from 
artesian  wells  proposed  for  this  city. 

' '  The  environment  which  gives  character  to  deep-ground 
water  is  such  that  this  class  of  water  cannot  be  consistently 
compared  with  either  surface  or  shallow- well  waters. 

"  Nitrogen  in  several  chemical  combinations  influences  the 
determination  of  the  quality  of  water  for  potable  purposes  more 
than  any  other  element  in  chemical  combinations,  since  it  is 
a  principal  constituent  of  the  decaying  organic  matter  with 
which  all  natural  waters  come  in  contact.  Whether  the  source 


WATER-SUPPLIES. 

of  this  organic  impurity  in  water  is  in  decaying  animal  or  vege- 
table matter,  chemistry  does  not  pretend  to  decide  definitely. 
So  much  of  the  organic  matter  as  is  absorbed  by  rain  falling 
in  the  open  country  is,  as  a  rule,  thoroughly  oxidized  and  con- 
verted into  the  harmless  inorganic  nitrogen  compound,  nitrates, 
by  intermittent  nitration  through  porous  surface  soils  in  the 
presence  of  air.  The  nitrates  in  shallow-well  waters,  accom- 
panied by  small  amounts  of  albuminoid  and  free  ammonia,  indi- 
cate a  high  degree  of  natural  purification  by  intermittent  fil- 
tration and  the  amount  of  previous  contamination  of  water  by 
dissolved  organic  matter.  Should  the  nitrates  be  accompanied 
by  a  considerable  amount  of  unstable  albuminoid  and  free  ammonia 
and  nitrites  there  is  evidence  of  recent  contamination.  The  free 
ammonia,  so  called,  is  in  itself  harmless,  and  its  presence  in  sur- 
face and  shallow-well  waters  is  simply  indicative  of  a  progressive 
natural  process  of  purification  of  water  that  contains  organic 
matter. 

"The  character  of  deep-well  waters  is  entirely  different. 
Because  of  the  usual  absence  of  free  oxygen  in  these  waters, 
nitrates  once  formed  by  intermittent  filtration  through  well- 
aerated  surface  soils  may  be  reduced  by  contact  with  mineral 
salts  and  organic  matter  deposited  in  deep  subsoils,  the  nitrogen 
reappearing  as  free  ammonia  in  considerable  quantities.  Waters 
of  this  class  may  safely  contain  free  ammonia  and  other  nitrogen 
compounds  in  quantities  which  from  a  chemical  view-point 
would  cause  suspicion  if  contained  in  shallow-well  and  surface 
waters. 

4 '  The  total  and  relative  amounts  of  the  nitrogen  compounds 
in  deep-well  waters  are  not,  therefore,  a  quantitative  indication 
of  past  pollution,  as  they  are  in  shallow-well  waters.  The  remote- 
ness of  the  source  of  these  constituents  is  in  itself  a  security 
against  dangerous  contamination. 

"A  determination  of  the  amount  of  combined  chlorine  in 
waters,  particularly  surface-waters,  is  very  often  valuable  in 
detecting  sewage  contamination;  but  in  coast  countries  and  in 
connection  with  artesian  well-waters  which  may  have  filtered 
through  soils  containing  saline  matter  it  loses  its  significance. 

"Total  solids  are  largely  derived  from  the  mineral  matter  in 


GROUND- WATER  SUPPLY.  9 

solution.  The  degree  in  which  they  will  affect  water  for  mechan- 
ical and  manufacturing  purposes  can  be  determined  by  chemical 
analysis.  If  contained  to  the  extent  of  making  a  water  unfit 
for  hygienic  purposes  the  water  becomes  unpalatable  as  a  rule. 

' '  The  analysis  of  many  samples  of  deep-well  waters  in  Eng- 
land, made  under  the  direction  of  the  'Rivers  Pollution  Com- 
mission on  the  Domestic  Water  Supplies  of  Great  Britain,'  lead 
to  the  following  conclusions,  namely:  'Of  the  different  varieties 
of  potable  waters,  the  best  for  dietetic  purposes  are  spring  and 
deep-well  waters;  they  contain  the  smallest  proportion  of  organic 
matter,  and  are  almost  always  bright,  sparkling,  palatable,  and 
wholesome,  while  their  uniformity  of  temperature  throughout 
the  year  renders  them  cool  and  refreshing  in  summer,  and  pre- 
vents them  from  freezing  in  winter.  Such  waters  are  of  ines- 
timable value  to  communities,  and  their  conservation  and  utiliza- 
tion are  worthy  of  the  greatest  effort  of  those  who  have  the  public 
health  under  their  charge.'  .  .  .  '  In  all  cases  in  which  spring 
and  deep-well  water  of  good  quality  are  available  we  recom- 
mend that  they  should  be  employed  in  preference  to  surface- 
or  river- water  for  domestic  supply.' 

"  The  fear  of  future  contamination  of  the  water-supply  from 
increased  population  and  cultivation  of  the  catchment  area 
is  very  remote,  since  the  prolonged  intermittent  filtration 
which  the  water  receives  tends  to  exhaust  or  to  render  harmless 
the  organic  matter  that  may  have  been  originally  dissolved, 
while  any  organic  matter  which  may  have  been  dissolved  from 
the  deep  subsoils  is  probably  of  a  vegetable  nature  and  harm- 
less. So  far  as  judgment  can  be  based  upon  a  single  chemical 
determination  of  the  nitrogen  compounds,  it  has  not  detected 
pollution  in  any  one  of  the  samples  of  the  local  deep-well  waters 
which  have  been  analyzed,  when  considered  from  the  standpoint 
of  deep- well  waters.  By  comparison  with  other  unpolluted  deep- 
well  waters,  the  local  waters  certainly  show  a  superiority. 

"Of  the  three  local  waters,  the  Tacquard  well  is  shown  by 
the  single  determination  to  be  the  best." 

The  late  Dr.  Drown,  formerly  chemist  to  the  State  Board 
of  Health  of  Massachusetts,  furnished  a  very  interesting  report 


I O  IV A  TER-SUPPLIES. 

upon  the  waters  of  the  Galveston  wells  at  a  somewhat  later  date 
than  the  report  on  the  preceding  pages.     It  follows  in  full. 

REPORT    OF    DOCTOR    T.     M.     DROWN,     OF    BOSTON,     MASS. 

"  MASSACHUSETTS  INSTITUTE  OF  TECHNOLOGY, 
BOSTON,  MASS.,  February  6th,  1893. 

"To  the  Honorable  Board  of  Commissioners  of  Water-works  of  the 
city  of  Galveston,  Texas. 

"  Gentlemen:  I  send  you  herewith  the  results  of  my  analyses 
of  the  samples  of  water  received  from  you,  bearing  on  the  ques- 
tion of  a  water-supply  for  Galveston. 

"  In  addition  to  the  sanitary  analysis  of  the  waters,  I  have 
made  a  sufficient  number  of  determinations  of  the  mineral  ingre- 
dients to  indicate  their  fitness  for  domestic  and  industrial  uses. 

"  From  the  table  of  analyses  it  will  be  seen  that  the  waters 
from  all  the  Hitchcock  wells  have  a  general  agreement  in  com- 
position. They  are  characterized  by  rather  high  contents  of 
alkaline  bicarbonates  and  chlorides,  and  low  contents  of  lime 
and  magnesia.  The  waters  should  be  classed,  therefore,  as 
'alkaline  saline.' 

"  I  have  taken  the  average  of  the  composition  of  these  five 
waters  as  probably  representing  better  the  supply  obtainable  by 
artesian  wells  in  this  locality  than  the  waters  from  any  one  well. 

"  i.  With  regard  to  the  sanitary  properties  of  the  Hitchcock 
waters,  the  amount  of  organic  matter  in  the  water,  as  shown 
by  the  albuminoid  ammonia  and  oxygen  consumed,  is  extremely 
small,  and  as  such  is  of  no  significance.  The  free  ammonia  is 
a  very  common  ingredient  in  deep  artesian  wells.  The  origin 
of  it  is  not  always  easy  to  explain,  but  it  certainly  has  no  con- 
nection with  recent  pollution,  the  only  connection  which  gives 
it  significance  in  surface-waters  and  shallow  wells.  There  is 
no  nitrogen  present  in  the  form  of  nitrites  or  nitrates.  The 
water  may  be  said,  therefore,  to  be  perfectly  satisfactory  as  far 
as  its  freedom  from  organic  matter  or  products  of  decomposition 
is  concerned.  I  do  not  think  our  knowledge  of  the  effects  on 
the  human  system  of  mineral  matters,  when  present  in  very 
small  amounts  in  drinking-waters,  is  at  present  very  extensive 
or  accurate.  I  know  of  no  instance  where  the  continued  use 


GROUND-WATER  SUPPLY.  H 

of  water  of  this  character  has  been  followed  by  injurious  results. 
If  we  deduct  the  amount  of  common  salt  in  the  average  of  the 
five  waters  from  the  total  solids,  we  have  34.43  parts  of  solid 
matter  remaining,  or  about  twenty  grains  to  the  gallon.  Assum- 
ing that  these  were  all  sodium  carbonate,  the  amount  taken 
into  the  system  in  the  regular  use  of  the  water  would  be  very 
small,  say  seven  to  eight  grains  a  day.  There  is  no  evidence 
that  I  know  of  to  indicate  that  this  could  prove  injurious. 

"2.  With  regard  to  the  technical  use  of  these  waters,  the  ad- 
vantage of  softness  in  water  is  one  that  cannot  be  overestimated. 
The  expense  and  annoyance  involved  in  the  use  of  hard  waters, 
both  in  the  household  and  in  industrial  works,  is  so  great  that  a 
water-supply  with  little  lime  and  magnesia  is  much  to  be  prized. 
The  most  injurious  scale-forming  ingredient  in  boilers  is  sulphate 
of  lime.  This  is  almost  entirely  absent  in  these  waters,  and  the 
lime  and  magnesia  in  the  form  of  carbonates  is  exceptionally 
small.  As  is  well  known,  carbonate  of  soda  is  added  to  hard 
waters  as  a  preventive  of  scale  in  boilers. 

"3.  With  regard  to  the  permanence  in  the  character  of  these 
waters  on  continued  pumping  I  am  not  able  to  form  an  opinion; 
time  alone  can  decide  this  question.  From  the  information  given 
by  your  engineer,  Mr.  Kiersted,  it  seems  to  me  very  unlikely  that 
the  amount  of  salt  will  increase  by  infiltration  from  the  sea.  But 
new  underground  areas  may  be  drawn  upon  which  contain  water 
of  different  character.  Thus  it  will  be  noticed  that  sample  No. 
8,  from  Tacquard's,  contains  considerable  iron,  which  is  absent,  or 
nearly  so,  in  the  other  samples.  When  iron  is  present  in  well-water 
in  sufficient  quantity  to  cause  a  precipitation  of  iron  rust,  the 
water  becomes  unfit  for  laundry  use.  The  amount  of  iron  in  this 
water  (No.  8),  0.0514  part  of  oxide  of  iron  in  100,000,  is  very  near 
the  limit  of  precipitation.  Again,  both  the  wells  of  Tacquard's 
yield  water  which  is  more  highly  colored  than  the  others,  and  in 
both  the  water  is  slightly  harder. 

"  I  do  not  know  whether  all  these  Hitchcock  wells  have  been 
in  continuous  use  for  a  sufficient  length  of  time  to  enable  one  to 
say  whether  the  character  of  the  water  they  now  yield  is  constant. 
If  not,  it  would  seem  to  be  prudent  to  pump  them  continuously 
to  their  maximum  capacity  for  some  weeks  to  discover  if  the 


12 


WA  TER-SUPPLIES. 


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GROUND-WATER  SUPPLY.  13 

water  changes  in  composition,  either  in  the  direction  of  improve- 
ment or  deterioration.  Any  well  yielding  water  high  in  iron  or  with 
iron  continuously  increasing  should  be  rejected. 

"  I  do  not  know  what  system  of  water- works  is  under  consider- 
ation, but  the  effect  of  the  exposure  to  light  and  heat  of  these 
waters  should  be  considered  if  open  reservoirs  are  contemplated. 
The  presence  of  free  ammonia  in  the  waters  would  afford  food  for 
the  growth  of  organisms,  which  might  impart  unpleasant  tastes 
and  odors  to  the  water. 

"  With  regard  to  the  other  samples  examined,  the  Dickenson 
well  is  almost  identical  with  the  waters  from  the  Hitchcock  wells 
Nos.  i,  6,  and  8.  The  water  from  Alva  is  decidedly  harder,  and 
therefore  much  less  desirable  for  general  use.  The  water  from 
Houston  is  of  an  entirely  different  character.  It  contains  much 
less  salt,  and  its  hardness  is  nearly  four  times  as  great  as  the 
Hitchcock  water. 

"  The  water  of  San  Jacinto  River  would  not  furnish  an  accept- 
able supply  without  extensive  settling-reservoirs  and  filter-beds, 
which,  in  connection  with  the  expense  involved  of  bringing  the 
water  sixty  miles,  would  probably  be  prohibitive. 

"In  conclusion  I  would  say  that,  in  my  opinion,  the  waters  from 
Hitchcock,  as  represented  by  samples  from  the  residence  of  Mr. 
Tacquard,  Wheeler's  well,  and  the  railroad  well,  would  in  their 
present  condition  make  a  satisfactory  water-supply  for  the  city  of 
Galveston  from  a  sanitary,  domestic,  and  industrial  point  of  view." 

The  general  superiority  of  ground-water  as  a  source  of  public 
water-supply,  hygienically  considered,  is  generally  accepted  by 
sanitarians.  But  how  far  considerations  of  quality  for  hygienic 
purposes  should  weigh  against  considerations  of  quality  for 
mechanical  purposes  without  prejudice  in  either  direction  is 
somewhat  of  an  open  question  from  other  standpoints.  As  a 
general  proposition,  a  quality  of  water  which  in  any  particular 
locality  will  serve  the  public  and  private  requirements  in  a  satis- 
factory degree  should  prove  the  most  valuable  as  a  commodity, 
particularly  if  it  be  of  attractive  appearance. 

A  naturally  clear,  soft,  wholesome  water  is  the  ideal  water. 
But  water  of  such  a  quality  is  accessible  to  but  comparatively 
few  communities.  Usually  there  is  a  wide  departure  of  the  quality 


14  WATER-SUPPLIES. 

of  available  water  from  that  of  ideal  water  in  some  one  or  more 
of  the  three  named  particulars,  but  as  a  rule  the  least  variation 
permissible,  popularly  considered,  is  in  the  clearness  of  the  water. 
A  very  slight  turbidity  will  arouse  a  suspicion  in  the  popular 
mind,  even  though  the  wholesomeness  of  the  water  may  be 
unimpaired  on  account  of  it,  and  quickly  offend  the  aesthetic 
taste. 

A  suspicion  of  pollution  or  an  offense  to  the  sense  of  sight 
becomes  all  the  more  intense  and  aggravated  if  aroused  periodically; 
that  is  to  say  if  turbidity  is  an  abnormal  condition  of  a  water-supply 
arising  occasionally  for  a  brief  interval,  a  comparison  of  the  con- 
dition of  the  water  then  with  a  normally  clear  water  is  so  strik- 
ing as  to  magnify  and  intensify  a  suspicion  of  serious  pollution. 
A  community  will  become  accustomed  more  readily  to  a  water 
somewhat  turbid  all  of  the  time  than  to  one  similarly  affected  a 
part  of  the  time.  Thus  the  turbidity  occasionally  noticed  in 
ground-water  drawn  from  a  shallow-water  supply  gallery  parallel 
with  a  river  and  the  accompanying  increase  of  bacteria  in  the 
water  may  be  due  to  too  high  a  rate  of  nitration  through  the  gravel- 
bed  separating  the  gallery  from  the  river.  This  changed  con- 
dition of  the  water-supply  becomes  at  once  apparent  to  every  con- 
sumer, and  without  knowing  the  facts  the  consumers  become  sus- 
picious of  pollution  and  are  quite  likely  to  suspect  a  direct  intake 
to  the  river,  accidental  or  otherwise,  to  meet  some  contingency  of 
water  service — a  suspicion  affording  ground  for  numerous  com- 
plaints and  unpleasant  rumors,  outspoken  complaint  of  improper 
management,  all  of  which  are  a  source  of  annoyance  and  often  of 
mutual  misunderstandings  between  the  water-works  management 
and  its  patrons.  But  in  any  event  a  judicious  water- works  manage- 
ment should  desire  to  avoid  either  a  suspicion  of  unwholesome- 
ness  or  an  offense  to  the  senses  by  serving  a  uniformly  clear  water, 
one  of  so  pleasing  and  attractive  appearance  that  its  use  as  a 
commodity  becomes  popular  quite  as  much  as  a  necessity. 

There  is  no  desire  to  be  understood  as  advocating  in  any  measure 
the  clearness  of  water-supply  as  a  disguise  for  unwholesomeness. 
It  is  mentioned  chiefly  as  a  quality  which  pleases  and  gives  general 
satisfaction  so  far  as  appearances  may  go,  and  to  this  extent, 
should  not  be  disregarded.  While  there  may  be  little  connection 


GROUND-WATER  SUPPLY.  15 

between  the  qualities  of  clearness  and  wholesomeness  hygienically 
considered,  still  it  is  known  that  the  provisions  which  are  often 
necessary  to  insure  clearness  often  suffice  to  insure  wholesome- 
ness,  as,  for  instance,  the  complete  removal  of  sediment  from  a 
turbid  river-water,  or  the  removal  of  iron  from  a  heavily  mineral- 
ized ground-water,  or  microscopic  life  from  a  natural  lake  or  reser- 
voir— in  fact  reflection  upon  the  matter  shows  that  the  instances 
where  a  clear  water  is  unwholesome  are  so  few  as  to  become 
notable  exceptions  wherein  individual  or  community  negligence 
may  be  a  contributing  cause. 

Many  recorded  instances  of  dangerously  polluted,  though  clear, 
well-water  lack  substantial  confirmation  of  the  source  of  pollution 
or  the  avenue  through  which  the  pollution  reaches  the  well.  It 
is  believed  with  a  host  of  observed  instances  to  confirm  the  belief, 
that  the  actual  source  of  well-water  pollution  is,  as  has  been  pre- 
viously stated,  through  direct  overflow  of  surface  drainage  or  a 
fissure  underflow  affording  almost  as  direct  communication  with 
the  well  as  the  surface  overflow.  This  is  stated  as  a  belief  for  the 
reason  that  no  matter  how  well  fortified  by  observation  the  state- 
ment may  be,  it  must  stand  in  this  day  and  generation  simply 
as  a  belief  until  by  confirmation  of  well-directed  scientific  proof 
it  becomes  recorded  as  a  matter  of  fact.  Exceptional  and  con- 
clusively proven  cases  of  well-water  pollution  can  neither  be 
construed  fairly  as  a  reason  for  wholesale  condemnation  of  well- 
water  supply  either  for  private  or  public  purposes,  nor  be  used 
sincerely  as  an  illustration  to  cast  suspicion  on  ground-waters  as 
a  class. 

It  is  seldom  that  we  can  gratify  our  desires  with  regard  to 
the  softness  of  ground-water,  as  the  character  of  water  partakes 
largely  of  the  geological  structure  of  the  ground  in  the  locality 
where  the  water-supply  is  developed.  The  highly  solvent  prop- 
erty of  water  renders  it  capable  of  retaining  dissolved  minerals 
with  a  tenacity  that  requires  the  exercise  of  something  like  the 
force  of  chemical  action  to  separate  them  from  the  water  and  to 
reduce  them  to  a  condition  in  which  they  can  be  mechanically 
removed  therefrom.  The  objection  to  any  process  of  this  kind 
is  to  be  found  in  the  fact  that  often  it  may  be  merely  a  substitu- 
tion of  one  mineral  for  another  or  that  the  expense  involved  in 


1 6  WA  TER-SUPPL1ES. 

the  chemical  process  is  either  prohibitive  or  no  less  than  the 
expense  of  repairs  resulting  from  the  use  of  a  hard  water.  Prob- 
ably the  expense  is  the  chief  objection  to  the  introduction  of 
most  water-softening  processes. 

Thus  far  the  softening  of  water  is  regarded  in  sort  of  a  rela- 
tive way  and  as  possessing  scarcely  a  determining  influence  in 
the  selection  of  a  public  water-supply.  It  will  doubtless  be  given 
greater  consideration  in  the  future  as  improved  and  less  expen- 
sive methods  of  water-softening  are  perfected  and  brought  to 
public  notice.  Efforts  in  this  direction  seem  to  have  been  largely 
confined  to  the  softening  of  water  for  industrial  use. 

It  is  not  intended  to  pursue  in  detail  this  subject  of  the 
quality  of  ground-water,  as  such  a  course  would  be  somewhat 
foreign  to  the  purpose  of  this  treatise  and  would  burden  the 
work  with  much  unnecessary  matter.  As  a  rule,  ground-water 
derived  from  a  district  suitable  for  water-supply  development 
is  hygienically  wholesome  when  proper  precautions  are  observed 
to  avoid  contamination  through  open  channels  connecting  the 
underground  flow  directly  with  the  surface  flow  or  run-off. 

Quantity. — The  amount  of  ground-water  that  is  available 
for  water-supply  purposes  is  a  perplexing  problem  to  the  minds 
of  many  a  water-works  management,  as  is  shown  by  the  many 
disappointing  failures  that  have  attended  efforts  to  secure  ground- 
water  supplies.  It  is  believed  the  problem  should  not  be  found 
so  perplexing  and  uncertain  of  solution  if  rationally  considered. 
A  few  fundamental  propositions  may  perhaps  aid  in  clearing 
away  some  of  the  perplexities.  For  instance: 

No  more  water  can  be  continuously  taken  out  of  the  ground  than 
goes  into  it. 

The  yield  of  the  ground-water  is  dependent  upon  the  character 
and  extent  of  the  catchment  area  and  depth  of  the  saturated  water- 
bearing  material. 

The  velocity  of  flow  of  ground-water  depends  upon  the  character 
of  material  through  which  it  must  pass  in  gravitating  from  a  higher 
to  a  lower  level. 

The  stability  of  the  ground-water  supply  depends  upon  the  three 
considerations  above  stated  as  well  as  upon  available  ground  storage 
at  the  point  selected  for  developing  the  water-supply. 


GROUND-WATER  SUPPLY.  17 

Were  these  several  considerations  kept  fully  in  mind  when 
contemplating  the  development  of  shallow-ground  water  there 
should  be  little  difficulty  in  approximating  correct  conclusions. 
They  possess  some  variations,  however,  which  it  is  necessary  to 
consider  as  we  proceed. 

The  amount  of  water  which  an  artesian  basin  can  furnish 
permanently  is  somewhat  uncertain  because  of  the  difficulty  of 
determining  the  several  governing  factors  above  outlined,  and 
therefore  becomes  a  matter  of  conjecture  except  where  com- 
plete geological  surveys  have  been  made,  which  is  a  work  usually 
undertaken  and  carried  out  only  by  the  general  government. 
It  is  not  unusual  to  find  artesian  districts  which  originally  sup- 
ported flowing  wells  so  overtaxed  by  the  exhaustion  of  accu- 
mulated water  storage  as  to  reduce  the  water  pressure  and  cor- 
respondingly the  available  flow  of  water  to  a  degree  that  requires 
the  use  of  pumping-engines  installed  at  considerable  depth  below 
the  ground  surface  to  maintain  the  supply  of  water.  In  most 
instances  a  reduction  of  pressure  and  of  flow  resulting  from 
constant  draft  should  be  anticipated  in  artesian  water-supply 
development  even  to  the  extent  of  sinking  an  intake  well  or 
installing  pumping  machinery  considerably  below  the  surface 
of  the  ground. 

Interesting  measurements  were  made  by  Professor  William 
D.  Pence  of  the  artesian  flow  from  wells  of  the  Hitchcock  group, 
near  Galveston,  Texas,  for  the  purpose  of  determining  the  flow 
of  water  at  different  elevations  between  the  surface  of  the  ground 
and  the  static  level  assumed  by  the  water  in  an  extension  of 
the  well-casing  above  the  ground. 

The  flow  of  the  well  ceased  at  a  height  of  about  30  feet  above 
the  surface  of  the  ground. 

In  the  following  tabulations  the  heights  represent  the  distance 
from  the  top  of  the  7J-inch  well-casing  near  the  surface  of  the 
ground  upward  to  the  several  centers  of  discharge  in  a  3-inch 
rising  pipe  tapped  into  a  cap  screwed  onto  the  well-casing. 


i8 


WATER-SUPPLIES. 


DISCHARGE  OF  ARTESIAN  WELL  AT  HITCHCOCK,  TEXAS,  MAY  19, 
1891.  MEASUREMENTS  TAKEN  WITH  TWO-INCH  EMPIRE 
METER. 

Height  above  top  of  well-casing.  Discharge  in  gallons  per  24  hours. 

28.00  feet  Scarcely  any 

25.35     M  8,022 

20.45     "  32,089 

15-55  40.000 

10-62  "                                             51,343 

5-26  70,551 

0.76  94,966 

DISCHARGE  OF  ARTESIAN  WELL  AT  HITCHCOCK,  TEXAS,  JUNE  5, 
1891.  MEASUREMENTS  TAKEN  WITH  FOUR-INCH  CROWN 
METER. 

Height  above  top  of  well-casing.  Discharge  in  gallons  per  24  hours 

28.00  feet  Scarcely  any 

20.4       "  28,245 

15-21  48,470 

10.63     "  67,320 

5-39     "  84,374 

1.03     "  98,616 

It  will  be  observed  that  the  discharge  varies  almost  directly 
with  the  pressure  or  head  and  that  for  each  one  foot  of  head 
or  equivalent  pressure  below  the  level  which  the  water  natu- 
rally assumes  in  the  stand-pipe  connected  with  the  well-casing 
there  is  an  equivalent  acceleration  of  discharge  of  about  3400 
gallons  per  twenty-four  hours;  for  instance,  if  the  discharge 
from  an  orifice  in  the  stand-pipe  one  foot  below  the  static  level 
of  water  therein  is  3400  gallons,  then  the  discharge  50  feet  below 
said  level  should  be  170,000  gallons  per  day  or  340,000  gallons 
at  a  level  100  feet  below  said  level. 

The  experience  with  artesian  wells  at  Memphis  indicates  a 
discharge  of  about  1,000,000  gallons  per  day  from  fifty  wells 
for  each  4  feet  of  draft,  or  a  rate  of  increase  of  about  5000  gal- 
lons per  twenty-four  hours  per  well  for  each  one  foot  of  draft. 


GROUND-WATER  SUPPLY.  19 

It  is  estimated  that  the  available  flow  from  a  single  pumping- 
station  of  the  Memphis  district  is  about  25,000,000  gallons  per 
day  under  a  draft  about  60  feet  below  static  water-level. 
In  the  Hitchcock  district,  where  the  available  draft  is  about 
50  feet,  the  station  yield  should  approximate  about  15,000,000 
gallons  per  twenty-four  hours.  But  the  water-supply  develop- 
ment need  not  be  confined  to  a  single  pumping-station  and  its 
group  of  wells,  as  in  an  extensive  artesian  district  auxiliary  sta- 
tions and  other  groups  of  wells  may  be  located  beyond  the  zone 
of  influence  of  the  first  group — possibly  several  miles  therefrom 
as  local  conditions  suggest — and  operated  by  power  transmitted 
from  the  original  or  central  station. 

Artesian  water-supplies,  particularly  those  derived  from  sand 
or  sand  rock,  are  exceedingly  desirable  and  should  be  developed 
to  the  highest  possible  degree  and  with  the  greatest  amount  of 
care.  They  can  scarcely  be  equalled  by  any  artificially  filtered 
surface-water  supply,  considered  hygienically. 


Shallow  ground-water  supplies  are  usually  developed  from 
sand  and  gravel  deposits  in  the  valleys  of  creeks  and  rivers.  In 
a  valley  where  the  stream  flows  over  a  rock  bed  the  sand  deposits 
are  thin  and  usually  so  exhaustively  drained  as  to  afford  but 
a  very  small  yield  of  water.  The  attempts  to  develop  a  public 
water-supply  in  valleys  of  this  character  have  failed  almost  with- 
out exception,  for  there  is  no  permanent  water  storage  of  any 
great  volume. 

Valleys  like  those  of  the  important  rivers  of  the  central  states 
often  possess  immense  deposits  of  sand  and  gravel  extending 
50  or  more  feet  below  the  river-beds.  These  deposits  afford 
immense  reservoirs  for  the  permanent  storage  of  water,  which 
can  be  drawn  upon  for  large  volumes  of  water  year  after  year 
with  no  fear  of  depletion.  The  valleys  of  the  Mississippi  and 
Missouri  Rivers  afford  a  striking  example  of  sand  deposits  of 
this  kind,  but,  strange  as  it  may  seem,  the  value  of  these  deposits 
as  sources  of  water-supply  has  as  yet  never  received  in  practice 
the  public  appreciation  they  deserve.  The  impression  seems  to 
prevail  in  communities  located  along  these  rivers  that  the  rivers 


2  o  WA  TER-SUPPLIES. 

themselves  are  the  best  available  source  of  supply,  and  immense 
sums  of  money  have  been  expended  in  the  erection  of  water  puri- 
fication works  without  a  thought  apparently  of  considering  the 
availability  of  a  clear  and  wholesome  supply  from  the  sand  beds 
beneath  the  rivers. 

Any  impression  that  the  deposits  are  generally  a  mixture  of 
alluvia  and  quicksand,  materials  which  are  known  to  be  altogether 
too  fine  for  the  free  flow  of  water,  is  erroneous.  While  deposits 
of  this  character  may  be  encountered  above  the  level  of  the  river- 
bed, it  is  generally  true  that  the  deeper  deposits  below  the  bed  of 
the  river  are  composed  very  largely  of  clean  coarse  sand  inter- 
mingled with  gravel.  Frequently  the  coarse  sand  is  in  strata 
separated  by  thin  layers  of  tenacious  clay.  In  some  districts 
along  the  Mississippi  River  the  deeper  deposits  for  20  to  30  feet 
are  composed  largely  of  heavy  gravel  and  sand,  with  scarcely  a 
suggestion  of  the  presence  of  quicksand.  The  heavy  and  coarse 
deposits  can  be  made  to  yield  a  large  supply  of  water  by  proper 
methods  of  development. 

In  estimating  the  available  yield  of  water  from  sand  deposits 
of  these  and  similar  river  valleys  the  matter  of  catchment  area 
is  scarcely  to  be  taken  into  consideration  outside  the  valley  proper, 
for  the  river  is  an  important  factor  in  keeping  the  sand  deposits 
supplied  with  water  should  they  be  drawn  upon.  The  situation  in 
this  regard  can  probably  be  more  clearly  presented  by  referring 
to  tests  made  for  the  purpose  of  developing  the  water-supply 
conditions  in  the  valley  of  each  of  the  two  rivers  named. 

In  1902  a  study  was  commenced  of  the  ground-water-supply 
conditions  of  the  Mississippi  River  valley  at  a  point  about  two 
and  one-half  miles  below  the  city  of  Muscatine,  Iowa,  having  in 
view  the  new  water-supply  works  for  that  city.  The  studies 
finally  resulted  in  a  decision  to  abandon  the  Mississippi  River,  the 
source  of  supply  for  twenty-five  years  of  the  original  water-works, 
and  to  develop  ground-water  at  the  site  of  tests  referred  to.  They 
also  developed  much  interesting  information  regarding  ground- 
water  conditions. 

Fig.  i  is  a  diagram  of  a  series  of  test  wells  excavated  to  bed- 
rock or  clay  on  a  line  about  right  angles  with  the  Mississippi 
River. 


GROUND-WATER  SUPPLY. 


21 


Each  well  after  reaching  the  rock  or  clay  substratum  was  with- 
drawn a  few  feet  to  admit  of  free  percolation  of  water  into  it,  except 
well  i,  which  had  a  strainer  about  8  feet  long  composed  of  three 
rings  of  vertical  slots,  nine  slots  to  each  ring,  J-  to  f  of  an  inch  wide 
and  respectively  2iJ,  24 J,  and  33 J-  inches  long,  each  ring  of  slots 
being  separated  by  8  or  10  inches  of  solid  metal.  The  combined 
area  of  the  slots  was  about  four  and  one-half  times  the  sec- 
tional area  of  the  8-inch  well-casing.  The  strainer  is  the  design 
of  William  Molis,  superintendent  of  water-works,  Muscatine,  Iowa. 


FIG.  i. 

Muscatine  Island  (island  in  name  only),  where  the  test  was 
conducted,  is  several  miles  wide,  with  a  slightly  undulating  sur- 
face. A  high- water  slough  skirts  the  bluffs  on  the  western  side  and 
the  Mississippi  River  washes  the  eastern  side  of  the  island.  The 
rainfall  upon  the  island,  which  is  not  evaporated  or  absorbed  by 
vegetation,  passes  almost  entirely  into  the  underflow;  scarcely 
any  of  it  disappears  in  surface  run-off. 

This  land  is  under  cultivation  for  the  raising  of  garden  truck 
and  accordingly  extensively  fertilized.     Storm- water  rapidly  dis 
appears,  showing  thorough  under  drainage. 

Plate  I  gives  an  idea  of  the  geological  structure  of  the  island, 
at  least  for  3000  feet  inland,  and  shows  a  vertical  section  along  the 
line  of  test-wells  and  soundings  of  the  Mississippi  River  to  the 
Illinois  shore.  It  also  serves  to  show  the  immense  permanent 
storage  capacity  of  the  gravel  deposits  below  the  low-water  stage  of 
the  river,  and  the  additional  temporary  storage  between  the  low- 
water  and  the  usual  high- water  marks.  The  tangible  value  of  even 
the  temporary  storage  is  not  to  be  underestimated  along  such  rivers 
as  the  Mississippi  and  Missouri,  for  as  we  write  the  Mississippi 
River  has  been  5  feet  or  more  above  low  water  for  nearly  a  year, 


w 


i 


vtroTOia  6-°s  IPM. 


GROUND-WATER  SUPPLY.  23 

and  accordingly  has  served  to  maintain  a  high  ground-water  level. 
However  the  temporary  storage  is  not  an  element  that  can  be 
depended  upon  for  water-supply  year  in  and  year  out,  for  during  the 
period  between  1878  and  1902  there  were  ten  years  when  the  average 
gauge-reading  of  the  Mississippi  River  at  Muscatine  was  below 
the  5-foot  stage  and  two  years  when  the  stage  of  the  river  was 
below  the  5-foot  mark  for  the  entire  year. 

The  problems  which  were  presented  for  solution  in  the  Muscatine 
study  of  ground-water  supply  are  the  same  as  those  presented  in 
other  similar  localities,  and  the  methods  there  pursued  are  char- 
acteristic of  those  which  may  be  pursued  elsewhere  with  such 
variations  as  may  suit  local  requirements.  In  general  the  essen- 
tial problems  for  solution  are  as  follows: 

1.  What  is  the  extent  and  available  depth  of  the  permanent 
ground-water  storage? 

2.  What  is  the  available  velocity  of  flow  through  the  deposits 
of  sand  and  gravel  underlying  the  river  valley  and  the  probable 
greatest  permissible  hydraulic  slope? 

3.  What  is  the  source  from  which  the  gravel-beds  are  supplied 
with  water  and  how  much  of  the  water  thus  supplied  is  avail- 
able for  use? 

4.  What  is  the  chemical  and  bacteriological  condition  of  the 
ground- water? 

5.  Is  there  danger  of  contamination  of  the  underflow  from 
drainage  of  the  city  above  or  from  farms  in  the  immediate  vicin- 
ity of  the  site  of  the  tests  and  observations? 

6.  What  extent  of  water-supply  development  work  is  required 
for  the  desired  supply  of  water  ? 

The  borings  were  made  for  only  a  distance  of  3000  feet  from 
the  river,  affording  information  of  a  practically  uniform  geological 
formation  of  the  lower  strata  of  water-bearing  material.  Private 
wells  for  a  radius  of  a  mile  or  more  from  the  site  of  the  tests, 
equipped  with  centrifugal  pumps,  showed  the  water-bearing  ma- 
terial to  continue  much  beyond  the  range  of  the  test-wells.  So 
far  as  could  be  ascertained  the  bed  of  the  Mississippi  River  is  of 
the  same  formation,  and  it  was  assumed  "the  gravel  formation 
extended  even  beyond  the  Illinois  side  of  the  river.  Therefore 
without  pursuing  investigations  to  actually  determine  the  full 


24  WATER-SUPPLIES. 

extent  of  the  gravel  deposits,  a  work  evidently  involving  large 
expense,  reasonable  assurance  was  developed  to  indicate  at  least 
two  square  miles  of  available  catchment  area  which  should  absorb 
sufficient  rainfall^  if  rainfall  only  could  be  relied  upon  to  support 
the  gravel-beds,  to  yield  at  least  454,000  gallons  of  water  per 
square  mile  of  catchment  area,  or  an  average  of  813,500  gallons 
per  twenty-four  hours,  the  smaller  computation  being  based  upon 
gj-  inches  or  35  per  cent  of  the  minimum  annual  rainfall,  and 
the  larger  amount  being  based  upon  15  inches  or  45  per  cent  of  the 
average  rainfall. 

The  local  conditions  seemed  to  require  a  basement  level  of 
the  pump-pits  at  about  6  feet  above  low  water,  and  the  pump- 
plunger  about  9  or  10  feet  above  low  water,  and  a  suction  draft 
to  a  level  10  feet  below  low  water  or  possibly  a  little  more. 

With  due  allowance  for  hydraulic  slope  of  the  ground-water 
the  available  permanent  storage  which  can  be  drawn  upon  in  ad- 
dition to  the  rainfall  yield  is  computed  at  130,000,000  gallons  per 
square  mile. 

During  the  months  of  September  and  October,  1902,  prac- 
tically simultaneous  observations  were  made  of  the  level  of  the 
water  in  the  nine  test-wells  and  of  the  river.  The  stage  of  the 
river  was  practically  constant  for  the  month  preceding  the 
beginning  of  the  observations.  The  period  covered  by  the  obser- 
vations embrace  a  period  of  rather  rapid  rise  of  the  river  and  a 
corresponding  fluctuation  of  the  ground-water  level  in  all  of 
the  test-wells. 

The  fourteen  representative  series  of  water-level  observa- 
tions are  represented  in  the  diagram,  Plate  II.  Other  observa- 
tions were  made  between  September  21  and  26,  in  connection 
with  a  pumping  test,  which  are  the  subject  of  special  comment 
further  on. 

The  four  water-surface  lines  of  September  6  to  13,  inclusive, 
show  a  pronounced  slope  of  the  ground-water  table  towards  the 
river  of  an  average  of  0.8  of  a  foot  in  1000  feet  and  necessarily 
a  movement  of  the  absorbed  rainfall  from  remote  points  of  the 
island  towards  the  river. 

A  rise  of  2  feet  in  the  river  between  September  13  and  21 
produced  a  corresponding  but  gradually  decreasing  rise  inland, 


(O          CS  OO  I—  C7         10          ' 

.TiTiTiTiTiT.iT.TiTn  111 


2  6  WA  TER-SUPPLIES. 

even  further  inland  than  well  9,  where  the  recorded  rise  was 
0.3  of  a  foot.  The  average  slope  of  the  ground- water  table 
between  the  dates  named  is  about  6  inches  per  1000  feet.  It 
is  observed  that  during  this  interval  of  progressive  rise  the  slope 
remains  downward  towards  the  river,  showing  a  persistency  of 
the  ground-water  to  advance  in  that  direction  notwithstanding 
the  check  imposed  by  the  rise  of  the  river.  This  check  or  damming 
of  the  ground-water  at  the  river-front  compelled  the  advancing 
underflow  to  fill  the  voids  of  the  sand  in  the  wedge  between  the 
water  planes  of  September  13  and  21.  In  order  to  accomplish 
the  filling  of  this  wedge  2  feet  in  height  at  the  river-front  and 
with  an  apex  about  3300  feet  inland,  the  water  in  the  saturated 
gravel  of  the  island  down  to  the  clay  substratum,  a  depth  of 
about  43.5  feet,  must  have  advanced  laterally  at  least  58  feet 
through  the  gravel  or  at  the  rate  of  7.25  feet  per  day,  or 
nearly  the  equivalent  of  2J-  feet  of  solid  water  43.5  feet  high 
after  making  correction  for  a  rainfall  of  ij  inches  during  the 
interval. 

As  the  river  continued  to  rise  the  slope  of  the  ground-water 
was  reversed  to  an  inclination  from  the  river  inland  about  Sep- 
tember 23,  and  continued  reversed  until  after  the  summit  of 
the  rise  was  reached  on  September  30.  The  average  inclination 
of  the  slope  inland  during  this  period  was  1.13  feet  per  1000  feet. 
The  advance  of  river-water  inland  to  fill  the  voids  in  the  sand 
between  the  curves  of  the  dates  named  is  computed  in  a  manner 
similar  to  the  above  computation  to  have  been  41.1  or  at  the 
rate  of  13.7  feet  per  day,  equivalent  to  4.6  feet  of  solid  water 
44  feet  high.  In  the  foregoing  computation  a  void  space  of 
one-quarter  the  mass  was  allowed  for  the  wedge  embraced 
between  the  several  ground-water  planes  in  order  to  allow 
for  moisture  permanently  retained  by  capillary  attraction, 
and  one-third  the  mass  was  considered  as  available  void 
space  in  computing  lateral  sectional  flow  through  saturated 
material. 

The  matter  may  be  put  into  convenient  shape  for  compu- 
tation by  means  of  the  Darcy  formula,  namely, 

v=kiy 


GROUND-WATER  SUPPLY, 


27 


wherein    v  =  velocity  in  feet  per  day; 

i  =  inclination  of  ground-water  surface  in  a  given  dis- 
tance divided  by  that  distance; 

.&=a  factor  depending  upon  the  porosity  of  material 
through  which  the  underflow  passes. 


Interval. 

V. 

Velocity  in  feet  per 
day  of  solid  water. 

*. 

Inclination. 

k. 

Factor. 

Septem 

<( 

3er  1  3  to  2  1  

2-5 

i-55 
4-63 

0.0005 
o.  000272 
o.  ooi  13 

5000 
5700 
4100 

20  to  21  

27  to  30  

Average  value  of  k  is  4900  in  round  numbers 

In  order  to  obtain  the  actual  advance  as  measured  in  the 
voids  of  the  sand  the  tabulated  velocities  should  be  multiplied 
by  3  and  the  corresponding  average  value  of  k  would  then  be 
14,700. 

During  the  interval  between  the.  dates  September  21  and  27 
the  condition  of  the  ground-water  table  was  observed  in  the 
several  wells  while  pumping  on  one  of  the  wells  was  in  progress. 
Plate  III  contains  a  diagram  showing  the  fluctuations  referred  to. 

A  centrifugal  pump  was  connected  directly  with  the  8-inch 
casing  of  No.  i  well,  the  details  of  which  well  are  described  on 
a  previous  page,  and  operated  practically  continuously  by  means 
of  a  belted  connection  with  a  traction-engine,  from  7  A.M.  of 
the  2ist  to  12  P.M.  of  the  26th,  one  hundred  and  twenty-five 
and  one-half  hours.  The  object  of  this  test  was  for  the  pur- 
pose of  deriving  information  regarding  the  porosity  of  the  gravel 
deposits.  Accordingly  the  actual  amount  of  water  pumped  from 
the  well  was  regarded  as  purely  an  incidental  matter  and  of  itself 
capable  of  furnishing  little  or  no  reliable  information  of  the  kind 
desired.  Such  approximate  measurements  as  were  made  of  the 
discharge  of  the  pump  as  the  water  passed  through  a  wooden 
flume  to  the  river  indicate  a  discharge  at  the  rate  of  1,500,000 
gallons  per  twenty-four  hours. 

An  interesting  fact  connected  with  the  test  is  the  one  that 
the  river  rose  over  3  feet  between  the  morning  of  the  2ist  and 
the  26th  and  that  a  corresponding  rise  was  observed  in  most 


mnnTT 


' 


nrmn 


\ 


\ 


\ 


-Well  No.9 


Well  No.  8 


Well  No.7 

Well  No.« 

Well  No.5 
Well  No.4 

Well  No.3 
Well  No.2 
Well  Nb.l 


GROUND- WATER  SUPPLY.  29 

of  the  wells  notwithstanding  the  large  amount  of  water  that 
was  abstracted  from  well  No.  i. 

Plate  III  shows  the  zone  affected  by  the  pumping  to  extend 
about  700  feet  from  the  pu^ip  well  and  to  present  a  face  about 
1400  feet  in  diameter  to  the  river-front.  The  depth  to  the  clay 
substratum  below  the  water-table  at  this  well  is  about  45  feet. 

When  pumping  ceased  at  12.25  P.M.  the  zone  of  depleted 
sand  as  the  result  of  pumping  was  about  1000  feet  in  diameter. 
Between  that  hour  and  4.30  P.M.  of  the  same  day  the  inflow 
from  the  river  so  filled  the  depleted  sand  that  there  was  a  con- 
tinuous slope  to  test- well  8  and  almost  a  level  water-table  for 
the  next  1500  feet  inland,  or  to  test-well  9.  On  the  morning 
of  September  27  the  influence  of  the  rising  water-table  caused 
by  inflow  of  water  from  the  river  became  decidedly  apparent 
at  and  beyond  test-well  8,  and  were  it  not  for  the  heavy  pump- 
ing of  the  preceding  days  the  water-table  would  doubtless  have 
presented  a  more  uniform  slope.  As  soon  as  pumping  ceased 
the  inflow  of  water  was  comparatively  heavy  and  must  have 
been  influenced  very  largely  by  the  steep  slope  which  then 
obtained  between  the  river-front  and  pump  well  No.  I  even  as 
late  as  the  morning  of  the  27th.  The  average  slope  between  12.25 
P.M.  of  September  26  and  7  A.M.  of  the  27th  was  2.8  feet  per 
1000  feet,  and  the  estimated  volume  of  the  cone  of  depleted 
sand  of  a  base  1000  feet  in  diameter  which  was  filled  with 
water  between  12.25  and  4.30  P.M.  and  of  the  wedge  between 
the  water-table  of  the  last  stated  hour  of  the  26th  and  that  of 
the  morning  of  the  27th  divided  by  48,000  square  feet  of  river 
frontage  gives  approximately  a  velocity  of  flow  through  the  sand  of 
45  feet  per  twenty-four  hours  or  about  15  feet  of  solid  water. 
From  these  data  we  compute  by  the  formula  v=ki  the  value  of 
the  coefficient  of  porosity  (k)  to  be  5360.  A  previous  method  of 
computation  gave  the  value  of  k  at  6200,  but  it  is  believed  the 
later  computation  fits  the  observations  more  correctly.  In  view 
of  these  computations  a  factor  of  porosity  4000  to  5000  appears 
to  suit  the  Muscatine  conditions  and  admits  of  the  following 
local  rule,  namely: 

Multiply  the  observed  slope  of  the  ground-water  table  expressed 
in  feet  per  1000  feet  by  the  factor  4  to  5  to  get  velocity  of  underflow 


WA  TER-SUPPUES. 


expressed  as  solid  water,  or  12  to  15  to  get  velocity  expressed  as  lateral 
movement  through  sand,  assuming  the  voids  in  sand  to  be  one-third 
the  mass. 

No  mechanical  analysis  was  made  of  the  Muscatine  gravels 
and  sands  at  the  time  of  the  tests  referred  to,  but  later  when 
excavating  for  a  permanent  water-supply  well,  several  samples  of 
the  sand  and  gravel  penetrated  by  the  boring  were  collected 
and  analyzed,  with  the  following  result. 

MECHANICAL   ANALYSES    OF   MUSCATINE    SAND   AND    GRAVEL. 


Number  of  sieve. 

Per  cent  of  sand  finer  than  stated  sieve  numbers. 

i. 

2. 

3- 

4- 

Rejected  by  6.  ... 
6    

I  O 

5-5 
94.2 

83-1 
63-3 
44.0 

i  .  i 
0.09 

0.  OO 

18.5 

80.  50 

58.08 

41    o 

32.4 
24.  1 

2.3 

0   35 
o.oo 

54-5 
45   5 
27   2 

Il'.l 
62 

2     O 
0  .2 

36.8 
63.2 
25-8 

7-6 
3-° 

O  .  2 

0  ,  02 

1  4 

18 

20         .     . 

40  

60  

So  

In  order  to  form  some  conception  of  the  classification  of  the 
Muscatine  sand  we  have  deduced  the  value  of  the  coefficient  of 
porosity  (k)  of  assorted  and  washed  sands  of  various  sizes  from 
the  tabulated  results  of  experiments  contained  on  pages  210,  21 1, 
and  244  of  Professor  F.  H.  King's  report  in  the  Nineteenth  Annual 
Report  of  the  Geological  Survey. 

The  factors  in  the  following  table  indicate  that  the  effective 
size  of  the  Muscatine  sand  should  be  about  the  grade  of  a  coarse 
concrete  sand,  the  nearest  tabulated  size  of  sand  being  0.7146 
millimeter,  which  is  little  less  than  one  thirty-second  of  an  inch 
or  somewhere  near  the  size  of  sand  which  will  pass  a  sieve  of  20 
meshes  to  the  lineal  inch  and  will  be  retained  by  one  of  40  meshes 
to  the  lineal  inch.  However,  the  analysis  of  the  Muscatine  sand 
indicates  a  coarser  grade  of  sand,  at  least  samples  3  and  4,  than 
that  indicated  by  the  table,  a  circumstance  due  no  doubt  to  the 
fact  that  the  sand  experimented  with  by  Professor  King  was  of 
uniform  sized  grains,  possessing  a  uniformity  coefficient  of  unity, 
while  the  Muscatine  sand  is  an  unassorted  sand  of  various  sized 


GROUND-WATER  SUPPLY. 


31 


grains.  It  should  be  recollected  that  the  velocities  stated  in  the 
following  table  are  measured  as  volume  of  solid  water  passing 
in  a  unit  of  time,  and  that  for  a  lateral  velocity  in  the  voids  of  the 
sand  the  tabulated  velocities  should  be  multiplied  by  about  3. 

FLOW  OF  WATER  THROUGH  SANDS  AND  SANDSTONES    IN   CUBIC  FEET  PER 
MINUTE  PER  SQUARE  FOOT  OF  SECTION  UNDER  A  PRESSURE  GRADIENT 

OF    I    IN     10. 


Series 
Number  of  sand  . 

Size  of  sand 
grains  in 
millimeter. 

Flow  in  cxibic 
feet  per  minute. 

* 
Velocity  in  feet 
per  24  hours. 
Grad.  i  in  10. 

* 
Value  of 
coefficient  (£). 

^o.  8  quartz  

2  .  54 

5.2268 

7  $26  .  6 

7^266 

7 

I.  808 

3-649 

/  o 
5254.6 

/    J 

52546 

6 

I-451 

1.8481 

2161.3 

21613 

Si 

1.217 

1.3582 

1955-8 

19558 

5 

1.095 

1.2232 

1761.4 

17614 

4 

0.9149 

0.8242 

1186.8 

11868 

3 

0.7988 

0.5084 

732.1 

7321 

2 

0.7146 

0'3295 

470.9 

4709 

I 

o  .  6006 

0.2321 

334-2 

3342 

0 

o  .  5169 

0.1767 

254.4 

2544 

IOO 

o.  1018 

o.  0041 

5-9 

59 

Dunville  sandstone. 

0.0363 

0.029 

°-3 

3 

Madison  sandstone  . 

0.0818 

o.  246 

2-5 

25 

*  Author's  Computation. 

In  this  connection  it  is  interesting  to  know  what  the  coefficient 
of  porosity  may  be  of  natural  sands  and  gravels.  Apropos  of 
this  part  of  our  subject  are  the  experiments  of  the  Metropolitan 
Water  and  Sewerage  Board  of  Boston,  Massachusetts,  conducted 
to  determine  the  rate  of  percolation  through  sand  and  soils,  sum- 
marized by  F.  P.  Stearns,  chief  engineer  of  that  Board,  as  follows: 

"Amount  of  filtration  in  gallons  per  day  through  an  area  of 
10,000  sq.  ft.  of  different  materials,  with  the  loss  of  head  of  i  foot 
in  10  feet. 

"Coarse     sand,  the  average  of  three  experiments.  . .  2,200,000 
Medium      "  "   six  400,000 

Fine  "  "   two  "  90,000 

Very  fine    "        "        "         "     "  "  7,200 

Soil  "        "         "      "  "  510" 

The  mechanical  analysis  of  the  several  grades  of  material 
above  described  is  not  given  in  the  article  referred  to,  but  the 
data  are  sufficient  for  the  computation  of  the  velocity  stated  in 
terms  of  solid  water  and  the  coefficient  of  porosity  as  follows: 


32  WATER-SUPPLIES. 

Velocity.  Coefficient  (£). 

Coarse  sand 29.3  293 . o 

Medium  sand 5.3  53.0 

Fine  sand 1.2  12.0 

Very  fine  sand o .  96  9.6 

Soil 0.0068  0.068 

It  is  seen  that  the  grade  of  sand  has  much  to  do  with  the  per- 
missible velocity  of  water  flowing  through  it;  that  is  to  say,  the 
coarser  the  sand  and  the  more  uniform  the  size  of  the  individual 
grains  of  sand  the  more  freely  does  water  flow  through  it.  As 
a  rule,  however,  a  sand  deposit  is  a  heterogeneous  mixture  of  inter- 
mingled large-  and  small-sized  grains.  If  the  small  grains  are  very 
fine  and  constitute  a  considerable  percentage  of  the  total  volume, 
the  voids  of  the  deposit  may  be  so  thoroughly  filled  as  to  admit 
of  but  slow  percolation,  notwithstanding  the  presence  of  even  a 
considerable  amount  of  coarse  gravel.  Instances  of  this  kind  are 
not  uncommon. 

A  striking  example  of  this  kind  is  to  be  found  in  the  following 
mechanical  analysis  of  a  sand  from  a  district  bordering  on  the 
Ohio  River. 

Sand  rejected  by  sieve  No.     6 36     per  cent. 

"      passed     "      "      "        6 64        "    " 


"       "      «      IO  ...........  c* 

"          "          "      "      "      14  ...........  53.3     "    " 

a  ti  n        u        it  -  «      u 


"              "              "  "  "  20  ...........  49.2  "  " 

"              "              "  "  "  40  ...........  34.7  "  " 

"  "  "  60  ...........  20.0  "  " 

"              "              "  "  "  80  ...........  16.5  "  " 

"      "      "    ioo  ...........  12.7     "    " 

The  12.7  per  cent  of  the  sand  which  passed  the  No.  ioo  sieve 
contained  a  considerable  amount  of  silt  which  by  washing  and 
re  weighing  was  found  to  be  about  2|-  per  cent. 

The  uniformity  coefficient  is  about  12,  indicating  a  heteroge- 
neous mixture  of  gravel  stones  of  considerable  size  with  a  highly 
assorted  sand  in  which  there  is  a  large  percentage  of  fine  grains. 

The  result  of  Allen  Hazen's  investigations  under  the  direction 
of  the  Board  of  Health  of  Massachussetts  indicates  that  the  finer 
10  per  cent,  of  the  sand  grains  controls  the  percolating  capacity 


GROUND-WATER  SUPPLY. 


33 


of  sand  and  gravel,  and  suggests  expressing  sand  texture  in 
terms  of  a  "uniformity  coefficient,"  found  by  dividing  the  size  of 
the  sand  grain  separating  the  coarser  40  per  cent  from  the  finer 
60  per  cent  by  the  size  of  the  grain  separating  the  finer  10  per 
cent  from  the  coarser  90  per  cent. 

It  seems,  however,  as  though  the  entire  relation  of  sand  texture 
might  be  more  conveniently  expressed  by  a  nomenclature  referring 
to  a  series  of  graduated  sieves  and  the  uniformity  coefficient  ex- 
pressed as  the  ratio  between  the  number  of  meshes  to  the  lineal 
inch  of  the  sieve  separating  the  coarser  90  per  cent  from  the  finer 
10  per  cent  and  the  number  of  meshes  to  the  lineal  inch  of  the 
sieve  separating  the  finer  60  per  cent  from  the  coarser  40  per  cent. 
The  author  suggests  a  nest  of  sieves  for  the  purpose  of  analysis 
graduated  100,  80,  60,  50,  40,  30,  20,  18,  10,  and  6  inches  respec- 
tively to  the  lineal  inch.  The  size  of  the  wire  entering  into  the 
construction  of  the  sieves  must  necessarily  vary  in  gauge  and 
should  be  fixed  in  accordance  with  some  practical  standard. 
Having  once  arrived  at  a  standard  nest  of  sieves  the  sand  can  be 
classified  as  No.  so  and  so,  corresponding  to  the  sieve  which  allows 
it  to  pass  after  a  definite  period  of  agitation  of  the  sieves  nested. 
Thus  a  sand  which  passes  a  No.  6  sieve  and  is  retained  by  a  No. 
10  sieve,  or  the  next  size  finer  whatever  it  may  be,  would  be  classi- 
fied as  No.  6,  etc. 

To  illustrate  the  method  reference  is  made  to  a  table  repre- 
senting a  mechanical  analysis  of  sand  from  a  series  of  borings  in 
the  valley  of  the  Misssouri  River  shown  graphically  on  Plate  IV. 
ANALYSES  OF  MISSOURI  RIVER  SANDS. 


No.  of  sieve. 

Per  cent  of  sand  finer  than  stated  sieve  number. 

Well 
No.  i. 

Well 
No.  2. 

Well 
No.  5. 

Well 
No.  6. 

Missouri 
River 
channel. 

Quicksand. 

Rejected.  . 
6  

3-°7 
96.93 
91-93 
85-97 
80.23 

73-12 

24.  12 
6.87 
4-OI 
2.16 

9-34 
90.66 
80.63 
72.24 
64.70 
55-70 
!7-32 

7.81 

5-60 
3-52 

20.82 
79.18 
64.05 
49.14 

37-89 
27  .  10 

3.87 

1.26 

0.91 
0.68 

O.O 
IOO.OO 

99.42 
98.82 
98.20 

97.07 

75.27 
17.81 

9-34 
4-94 

5-94 
94.06 
87.25 
80.13 
73-48 

65-95 

29.07 

12  .07 

8.44 
5-69 

IOO.OO 
96.17 
85.46 
65-54 
40.92 

10  

id. 

18  
20  
40  
60  

80  

loo    

Borings  along  the  Missouri  River  near  Fort  Leavenworth. 


34 


GROUND-WATER  SUPPLY. 


35 


Upon  platting  the  percentages  corresponding  to  the  above- 
stated  sieve  sizes  and  connecting  the  consecutive  points  so  platted 
the  sieve  number  may  be  read  off  corresponding  to  the  effec- 
tive size  of  the  sand,  or  that  which  separates  the  finer  10  per  cent 
from  the  coarser  90  per  cent,  also  the  sieve  number  correspond- 
ing to  the  separation  of  the  finer  60  per  cent  from  the  coarser  40 
per  cent.  Dividing  the  former  by  the  latter  gives  the  uniformity 
coefficient.  The  following  table  expresses  the  results  of  the 
platting  of  the  preceding  table. 


No.  of  test-well. 

Sieve  corresponding  to  the 
separation  of 

Uniformity 
coefficient. 

Approximate 
effective  size 
in  millimeter. 

Finer  10%  from 
the  coarser  90%. 

Finer  60%  from 
the  coarser  40%. 

I            

54-5 
56  .0 

34-5 
79.0 
72.0 

25.2 
19  .O 

"•5 

45-5 
23-5 

2  .  12 

2-95 
3-00 
1-74 
3-07 

0.36 
o-35 
o-55 

0.21 

o.  29 

2               

c     . 

6 

Missouri  River.  .  .  . 

In  order  to  show  the  relation  between  the  sieve  number  and 
the  effective  size  of  the  sand  grain,  the  tabulated  results  of  Allen 
Hazen's  experiments  in  the  mechanical  analysis  of  sands  con- 
tained in  the  Twenty-fourth  Report  of  the  State  Board  of  Health 
of  Massachusetts  have  been  platted,  and  from  the  diagram  so 
constructed  there  has  been  tabulated  the  relation  above  referred 
to  over  as  wide  a  range  as  it  is  necessary  to  consider  in  practice. 
The  table  follows. 

TABLE    SHOWING    THE    RELATION     BETWEEN    THE    SIEVE   NUMBER    AND    THE 
EFFECTIVE  SIZE  OF  SAND  GRAINS. 


Sieve  No. 

Effective  size  in 
millimeter. 

Sieve  No. 

Effective  size  in 
millimeter. 

140 

0-135 

40 

0.46 

120 
100 

90 

0-155 
0.18 
o.  20 

3° 

20 

18 

0.71 

o.  96 

I  .  IO 

80 

O.  22 

14 

1-52 

70 
60 

0.24 
0.32 

10 

6 

2.04 
3-9° 

50 

o-39 

3  6  WATER-SUPPLIES. 

The  essential  advantage  to  be  derived  in  a  classification  of 
sand  by  the  sieve  number  is  that  that  nomenclature  is  more  gen- 
erally understood  and  is  in  close  association  with  the  only  appa- 
ratus that  is  usually  available  in  field  operations  of  the  mechanical 
analysis  of  sand. 

The  method  may  be  carried  a  step  farther  and  a  series  of 
factors  deduced  by  which  the  measured  slope  of  the  ground-water 
table  may  be  multiplied  to  give  the  velocity  of  underflow  and 
furthermore  these  factors  may  be  tabulated  in  conjunction  with 
corresponding  sieve  numbers  in  a  manner  to  facilitate  the  work 
of  computation. 

There  has  been  already  given  a  series  of  such  factors  (k)  in 
formula  v  =ki  in  the  table  expressing  the  results  of  Professor 
King's  experiments  on  page  31.  However,  these  factors  repre- 
senting the  condition  of  minimum  resistance  offered  by  sand  to 
the  flow  of  water  are  not  generally  applicable,  for  the  reason 
that  they  represent  a  measure  of  the  resistance  of  sorted  sands 
of  uniform  grain  possessing  a  uniformity  coefficient  of  unity 
which  is  a  condition  of  material  not  encountered  in  field  oper- 
ations. 

Allen  Hazen  gives  a  formula  for  the  flow  of  water  through 
unassorted  sands  as  follows: 


*Fahr.+io 
60 


\ 
)' 


where  v  is  the  velocity  of  water  in  meters  daily  in  a  solid  column 
of  water  of  the  same  area  as  that  of  the  sand, 

c  is  a  constant  factor  which  present  experiments  indicate 
to  be  approximately  1000, 

d  is  the  effective  size  of  sand  gains  in  millimeters, 

h  is  the  loss  of  head, 

/  is  the  thickness  of  sand  through  which  water  passes, 

t  is  the  temperature   (Fahr.)- 

Assume  a  temperature  t  of  50  degrees,  which  is  approximately 
the  temperature  of  ground-water,  and  that  the  entire  head  or 
pressure  of  water  for  a  depth  equal  to  the  thickness  of  sand  is 
consumed  in  producing  velocity,  as  would  be  the  case  of  ver- 


GROUND- WATER  SUPPLY. 


37 


tical  flow  with  unobstructed  discharge  in  a  layer  of  sand  satu- 
rated to  the  top,  then  Hazen's  formula  reduces  to  the  simple 
expression  v  =cd2,  the  factors  cd2  being  equivalent  to  k  for  ver- 
tical flow  in  the  Darcy  formula  previously  described. 

Upon  using  the  values  of  effective  size  for  which  the  corre- 
sponding sieve  numbers  are  known,  as  given  on  page  35,  and 
interpolating  for  intermediate  sieve  numbers,  we  have  the  results 
expressed  in  the  following  table. 

VALUES    OF    COEFFICIENT    OF    RESISTANCE    k    IN    FORMULA    v  =  ki,  COR- 
RESPONDING TO  STATED  SIEVE  NUMBERS. 


No.  of  sieve. 

k 

No.  of  sieve. 

k 

No.  of  sieve. 

k 

6 

49889 

24 

2474 

60 

336 

8 

3!77° 

26 

22OO 

70 

189 

10 

13650 

28 

1926 

80 

159 

12 

10614 

3° 

1653 

90 

131 

14 

7578 

32 

1461 

IOO 

106 

16 

5773 

34 

1269 

I2O 

79 

18 

3969 

36 

1077 

I4O 

60 

20 

3022 

40 

694 

2OO 

40 

22 

2748 

50 

499 

EXAMPLE. — The  velocity  of  flow  through  a  sand  90  per  cent 
of  which  by  weight  is  retained  by  a  No.  60  sieve  when  the  ground- 
water  slope  is  i  foot  in  1000  feet  is  v  =336x1/1000  =0.336  feet 
per  day  of  solid  water  or  i  foot  per  day  in  terms  of  the  voids  in 
the  sand. 

EXAMPLE. — What  is  the  grade  of  the  sand  which  with  a  slope 
of  i  foot  in  100  feet  admits  of  a  velocity  of  10  feet  per  day  in 

terms  of  void  space?    In  this  case  —  =k or  k  =333,  correspond- 
ing to  a  number  60  sand  in  preceding  table. 


A  recent  experiment  to  determine  the  flow  of  water  through 
a  No.  55  sand  resulted  in  a  measured  vertical  velocity  of  flow 
of  511  feet  of  a  solid  column  of  water  when  the  water  covered 
the  sand  to  a  depth  of  14^  inches  and  a  corresponding  value 
of  k  of  425  for  sand  just  covered  with  water,  the  uniformity 
coefficient  being  2.1. 

Upon  platting  the  results  of  the  analysis  of  the  Musca- 
tine  sand  as  tabulated  on  page  30  the  following  table  is  de- 
rived. 


38  WATER-SUPPLIES. 

EFFECTIVE  SIZE  AND  UNIFORMITY  COEFFICIENT  OF  MUSCATINE  SANDS. 


Sample. 

Sieve  corresponding  to  the  separation  of 

Uniformity 
coefficient. 

Approximate 
effective  size 
in  millimeters. 

Finer  10%  from 

Finer  60%  from 

coarser  90%. 

coarser  40%. 

I 

32.0 

15-° 

2  .  I 

0.81 

2 

33-° 

9-5 

3-5 

0.86 

3 

17.0 

I  .  20 

4 

13-5 

6.25 

2.0 

i-59 

Now  it  will  be  remembered  that  the  value  of  k  in  the  for- 
mula v  =  ki  as  found  by  computation  based  upon  water-level 
measurements  was  4900  for  velocity  in  terms  of  a  solid  column 
of  water.  The  same  factor  k  computed  from  the  table  of 
coefficients  on  page  37  for  the  sieve  numbers  32,  33,  17,  and  13.5 
is  respectively  1461,  1365,  4871,  and  8337,  or  an  average  of  4008 
without  regard  to  the  respective  depths  of  the  several  grades 
of  water-bearing  sand,  which  information  just  at  present  is  not 
available,  but  which  when  definitely  known  will  doubtless  modify 
somewhat  this  value  of  k. 

Serviceable  water-bearing  sands  are  seldom  finer  than  No. 
70,  and  usually  of  a  range  of  60  to  30.  Deep  beds  of  water-bear- 
ing gravel  and  sand  like  the  Muscatine  deposits  are  rather  excep- 
tional. 

The  water-bearing  capacity  of  a  sand  is  an  essential  con- 
sideration in  judging  of  its  value  for  water-supply  purposes,  for 
unless  it  is  of  a  grade  which  will  admit  of  a  free  circulation  of 
water  the  results  of  water-supply  development  may  be  very 
disappointing.  Wherever  the  natural  velocity  of  underflow  and 
the  slope  of  water-table  can  be  measured  with  a  reasonable  degree 
of  approximation,  it  is  best  to  take  these  measurements,  as  they 
offer  direct  evidence  of  the  flow  through  the  sand  deposits.  But 
such  measurements  are  not  always  feasible  and  usually  some 
substitute  must  be  accepted.  The  best  substitute  is  that  of  a 
careful  mechanical  analysis  and  a  survey  of  the  sand  deposit  of 
sufficient  extent  to  admit  of  capacity  determination  of  the 
character  herein  described. 

Direct  pumping  from  a  well  seldom  furnishes  reliable  evi- 
dence of  the  permanent  supplying  capacity  of  sand  deposits 


GROUND-WATER  SUPPLY.  39 

unless  continued  for  a  long  period  of  time,  much  longer  in  fact 
than  is  afforded  most  investigators  of  water-supplies.  The 
results  determined  by  pumping  are  usually  in  excess  of  the  per- 
manent yield  by  the  amount  of  water  contributed  to  the  well 
from  local  storage.  For  instance,  if  one  were  to  attempt  to 
determine  the  flow  of  water  into  a  pond  by  pumping  from 
the  pond,  it  is  evident  that  so  long  as  the  level  of  the  water  was 
depressed  as  the  result  of  pumping,  a  draft  is  made  upon  storage 
and  the  volume  of  water  delivered  by  the  pumps  is  in  excess 
of  the  actual  inflow  and  will  continue  to  be  in  excess  until  the 
level  of  the  pond  ceases  to  fall  or  the  storage  is  completely  ex- 
hausted. The  same  principle  holds  true  in  pumping  from  a 
well.  The  storage  in  the  sand  about  the  well  augments  the 
yield  of  the  well  and  will  continue  to  do  so  until  exhausted  and 
a  stable  water-table  is  established  in  the  sand  deposit.  How- 
ever a  long  period  of  time  is  sometimes  required  to  estab- 
lish a  stable  water-table  for  the  reason  that  available  storage 
extends  a  considerable  distance  from  the  well  and  gives  up 
its  water  in  a  progressively  decreasing  volume  moving  at  a  low 
velocity. 

A  short- time  pumping  test  furnishes  direct  information  of 
value  when  observations  are  made  of  the  curve  assumed  by  the 
water  in  the  ground  approaching  the  well.  A  steep  or  abrupt 
pitch  downward  toward  the  water  surface  in  the  well  over  a  com- 
paratively restricted  circumscribing  area  indicates  a  fine  sand 
of  high  resistance,  while  a  flatter  pitch  covering  a  more  extensive 
area  affords  information  of  the  presence  of  a  coarse  sand  of  com- 
paratively low  resistance.  It  is  apparent  therefore  that  for 
a  given  rate  of  yield  a  fine  sand  deposit  must  be  much  deeper 
theoretically  than  a  similar  deposit  of  coarse  sand. 

There  are  records  of  cases  where  the  depletion  of  ground 
storage  as  the  result  of  continuous  draft  has  been  so  gradual 
as  to  extend  over  a  period  of  several  years,  showing  conclusively 
the  erroneous  conception  which  usually  arises  from  the  results  of 
short-period  pumping  tests. 

A  tunnel  driven  under  a  mountain  will  often  open  subter- 
ranean fissures  from  which  water  flows  into  the  tunnel  in  great 
volumes  for  a  considerable  period  of  time  and  finally  dwindles 


40  WATER-SUPPLIES. 

down  to  a  comparatively  insignificant  flow.  Other  instances  of 
a  similar  character  are  encountered  when  shafts  have  been  sunk 
into  water  bearing  sand  rock  and  tunnels  driven  laterally  for  a 
considerable  distance.  At  first  water  flows  abundantly,  but  as  the 
draft  continues  and  the  water  pressure  falls  as  the  natural 
storage  is  depleted,  the  flow  diminishes  and  finally  must  be  re- 
duced to  the  annual  rainfall  supply.  Similar  experience  has  fol- 
lowed the  use  of  filter  galleries  in  sand  and  gravel  deposits — all 
going  to  show  that  a  study  of  the  mechanical  make-up,  depth 
and  extent  of  water-bearing  deposits,  as  well  as  available  ground- 
water  slope,  constitute  essential  elements  of  study  in  formulating 
correct  conclusions  with  regard  to  the  probable  permanent 
yielding  capacity.  These  observations  have  their  exceptions, 
as,  for  instance,  when  water  is  taken  from  a  well  penetrating 
the  permanent  storage  deposits  underlying  such  rivers  as  the 
Missouri  and  Mississippi,  hereinbefore  alluded  to;  for  then  the 
influence  of  the  river  has  a  pronounced  effect  in  restoring  rapidly 
the  depleted  storage  resulting  from  a  heavy  draft  upon  ground- 
water.  The  Muscatine  studies  afford  a  striking  example  of  river 
influence  as  shown  by  the  diagram  representing  the  result  of  these 
studies.  It  is  seen  that  under  normal  conditions  there  is  a  pro- 
nounced slope  and  flow  of  ground-water  towards  the  river,  and  it 
is  obvious  that  the  inclination  of  the  ground-water  table  riverward 
must  be  modified  both  by  a  departure  of  rainfall  from  the  normal 
and  by  river  fluctuation,  with  a  tendency  to  flatten  during  a  drought 
and  a  prolonged  stable  stage  of  the  river.  It  is  also  clear  that  a 
rapid  rise  of  the  river  dams  the  ground-water,  checks  its  advance 
towards  the  river,  and  by  back  pressure  causes  the  water  to  rise 
vertically  in  the  ground  for  a  long  distance  back  from  the  river, 
thereby  reducing  the  inclination  of  the  water-table  and  finally 
reversing  the  slope  should  the  rise  continue.  During  the  exist- 
ence of  reversed  slope  of  the  water-table,  water  from  the  river 
forces  itself  into  the  gravel-beds  and  drives  back  the  ground-water 
in  a  retreating  wave.  Thus  retreating  and  advancing  waves  of 
ground-water,  gradually  tailing  out  as  they  advance  inland,  beat 
time  to  the  fluctuation  of  the  river.  Certainly  the  influence  of 
rivers  upon  storage  of  water  in  the  ground  is  pronounced,  and  is  a 
factor  of  support  which  can  be  depended  upon  in  years  of  abnor- 


GROUND-WATER  SUPPLY.  41 

mally  low  rainfall  so  long  as  the  gravel  deposits  extend  well  below 
the  river-bed  and  afford  permanent  storage. 

Whatever  support  such  deposits  of  gravel  receive  from  the 
river  naturally  may  be  expected  to  operate  when  artificial  con- 
ditions are  created  by  drawing  water  from  the  ground  storage 
reservoirs  to  whatever  depth  may  be  found  practicable.  The 
river  inflow  to  restore  depleted  storage  is  pronounced  and  effec- 
tive and  proportionately  eliminates  the  necessity  of  considering 
extensively  the  catchment  area  and  the  amount  of  rainfall.  The 
velocity  of  flow  of  such  rivers  as  the  two  referred  to  is  sufficient 
to  prevent  a  silting  of  the  bed  of  the  river,  inasmuch  as  it  is 
naturally  much  in  excess  of  any  percolating  velocity  which  can 
originate  in  the  passage  of  river-water  downward  through  its  bed 
to  supply  any  near-by  artificially  depleted  storage. 

Sluggish  and  muddy  streams  may  accumulate  a  layer  of  silt 
over  the  bed  which  at  ordinary  stages  of  water  interferes  with 
replenishment  of  depleted  storage  in  neighboring  deposits  by  in- 
flow from  the  stream.  In  such  instances  the  basis  of  computa- 
tion of  available  yield  must  be  based  largely  upon  absorbed  rain- 
fall. Likewise  the  basis  of  computations  for  the  sand  and  gravel 
deposits  often  encountered  in  territory  bordering  the  coast  must  be 
the  absorbed  rainfall. 

Thus  it  is  found  in  these  instances  that  a  mechanical  analysis 
of  the  water-bearing  material,  its  depth  and  extent,  the  natural 
slope  of  the  water-table  and  the  velocity  of  underflow,  are  im- 
portant factors  for  the  determination  of  permanent  yielding 
capacity.  The  slopes  of  the  water-table  and  accordingly  the 
velocity  of  underflow  will  be  found  to  possess  seasonal  and  period- 
ical variations,  often  compelling  a  draft  upon  storage  for  a  con- 
siderable period  of  time  to  furnish  the  desired  yield.  It  is  im- 
portant to  determine  the  probable  extent  to  which  natural  storage 
may  be  thus  drawn  upon  without  permanently  depleting  it;  that 
is  to  say,  without  exceeding  the  replenishing  capacity  of  the  rain- 
fall during  the  wetter  periods. 

The  dry- weather  flow  of  streams  is  an  index  of  the  volume  of 
underflow,  and  therefore  a  careful  gauging  of  those  streams  which 
drain  a  limited  territory  affords  information  of  the  rainfall-absorb- 
ing characteristics  and  yielding  capacity  of  restricted  areas. 


42  WATER-SUPPLIES. 

Such  studies  are  best  adapted  on  a  limited  scale  to  streams 
draining  comparatively  small  catchment  areas  through  which  the 
meteorological  conditions  are  generally  the  same.  However  when 
facilities  admit  of  extensive  observation  a  measurement  of  the 
increment  by  which  the  flow  of  a  stream  progressively  increases, 
affords  information  of  the  volume  of  underflow  entering  even  large 
streams  draining  extensive  territory. 

A  hydrological  survey  of  territories  and  districts  with  a  view 
of  determining  underground  run-off  of  rainfall  is  a  question  which 
has  engaged  the  attention  of  but  few  communities  in  this  country. 
Therefore  when  a  specialist  is  called  upon  to  give  advice  with 
regard  to  the  feasibility  of  a  ground-water  supply,  there  is  usually 
a  dearth  of  information,  except  that  of  a  very  general  character, 
often  confined  solely  to  rainfall  statistics  collected  by  the  meteoro- 
logical department  of  the  general  government.  The  gauging  of 
streams  and  other  necessary  accompanying  measurements  or 
observations  in  order  to  secure  complete  data  of  the  locality  is  a 
matter  which  usually  cannot  be  undertaken  in  the  limited  time 
available  when  a  project  for  water- works  is  first  carried  out,  and 
as  a  rule  the  first  steps  are  usually  guided  by  and  based  upon 
an  analysis  of  such  general  information  as  can  be  gathered,  to- 
gether with  the  facts  and  data  bearing  upon  the  subject  which 
may  have  been  collected  elsewhere.  The  experience  of  com- 
munities with  ground-water  supplies  is  often  very  disappointing — 
perhaps  no  more  so  with  ground-water  than  with  other  sources 
of  water-supply — but  nevertheless  serious  and  tangible  enough 
to  affect  the  interest  of  the  entire  community  and  to  arouse  doubts 
of  the  expediency  of  making  further  efforts  of  improvement  along 
the  line  heretofore  pursued.  A  systematic  water- works  and  water- 
supply  record  maintained  from  year  to  year  showing  in  detail 
the  technical  history  of  the  water-supply  plant  would  serve  greatly 
in  solving  many  perplexing  local  problems.  Unfortunately  such 
records  are  not  always  available,  and  frequently  after  years  of 
experience  only  meager  general  information  is  still  all  that 
is  available  to  guide  in  an  improvement  of  the  water-supply 
works.  However,  where  detailed  information  is  lacking,  it  is 
always  profitable  to  supply  its  place  by  such  well-directed  tests 
and  observations  as  time  and  facilities  may  admit.  The  nature  of 


GROUND-WATER  SUPPLY. 


43 


some  of  the  detailed  information  that  is  desirable  and  which  can 
be  acquired  by  comparatively  inexpensive  tests  has  been  already 
pointed  out.  But  in  addition  to  this  information  a  sanitary  sur- 
vey of  the  site  of  a  proposed  ground-water  supply  should  be  made 
to  determine  both  the  area  and  physical  make-up  of  the  catch- 
ment basin,  particularly  when  the  balancing  effect  of  a  near-by 
large  river  upon  the  ground- water  storage  is  not  available.  In 
this  case  rainfall  must  be  the  sole  reliance  of  a  ground-water  supply. 
The  soil  in  the  catchment  basin  which  collects  the  rainfall  must 
be  porous  enough  to  absorb  a  considerable  percentage  of  the 
water  and  the  geological  substructure  of  a  character  which 
admits  of  the  necessary  free  lateral  movement  of  the  ground- 
water  towards  the  site  selected  for  developing  the  water-supply. 
There  is  a  wide  difference  in  absorbing  capacity  of  the  soils 
and  sands,  a  difference  which  is  well  exemplified  in  the  experi- 
ments of  Stearns,  before  alluded  to  on  a  previous  page  of  this 
chapter.  Upon  tabulating  the  results  of  these  experiments  in 
a  manner  to  show  the  rate  of  vertical  percolation  (which  is  about 
ten  times  the  rate  determined  by  the  experiments  at  a  grade 
of  i  in  10 )  some  idea  may  be  formed  of  the  relative  porosity  of 
sand  and  soils. 

PERCOLATING  CAPACITY  OF  SOILS. 


Material. 

Rate  of  vertical 
absorption  in  feet 
per  day. 

Ratio  of  absorption. 

Coarse  sand  

2Q3  .  3 

4?  14 

Medium  sand  

ZT.  .  "2 

784 

Fine  sand  

12  .O 

176 

Very  fine  sand  
Soil 

o.  96 

0.068 

14 

I 

The  results  of  another  experiment  by  Professor  King  to  de- 
termine the  rate  of  percolation  through  a  sandy  soil  covered  with 
a  yellowish  sand  are  given  in  the  table  on  page  44. 

We  must  remember,  however,  that  the  laboratory  experiments 
to  determine  the  rate  of  percolation  through  unassorted  sand 
and  soils  do  not  take  into  consideration  the  modifying  effects 
of  natural  conditions  such  as  frost  action,  vegetable  growth,  the 
intermittent  and  variable  intensity  of  the  application  of  water 


44 


WATER-SUPPLIES. 


which  occurs  naturally  through  the  rainfall;  in  both  these  experi- 
ments the  water  was  fed  continuously  to  the  material  experi- 
mented with.  Relatively  the  experiments  are  valuable  sugges- 
tions and  seem  to  show  that  a  collecting  area  which  is  desirable 
for  the  absorption  of  rainfall  should  be  of  a  sandy  texture.  The 
close-grained  soils  where  clay  generally  predominates  are  con- 
trolled largely  by  the  laws  of  capillarity  and  admit  of  but  an 
exceeding  slow  rate  of  percolation. 

PERCOLATING  CAPACITY  OF  SOILS. 


Section  of  pit. 

Effective  size  of  soil  grains  in  millimeters. 

Percolation  per  24 
hours  in  inches  of  water. 

Lower  soil. 

Upper  soil. 

I 

2 

3 

4 

0.0338 
0.0414 
0.0405 
0.0526 

0.2844 
o.  2844 
o.  2844 
o.  2844 

Average.  .  . 

6.7 
10.  104 
12.151 

12.678 

10.408 

In  field  operations  only  a  fraction  of  the  rainfall  is  absorbed 
by  the  underflow  even  in  porous  soils,  the  balance  disappearing 
as  surface  run-off  or  evaporation  and  absorption  by  plant  life. 

In  irrigated  sections  in  Colorado,  Professor  L.  G.  Carpenter's 
measurements  show  a  return  to  the  rivers  of  30  per  cent  or  more 
of  the  water  applied  for  irrigation  where  the  depth  of  the  annual 
application  of  water  to  land  aggregates  about  30  or  more  inches; 
the  measurements  also  indicate  a  return  to  the  river  by  under- 
flow of  i  cubic  foot  per  second  constant  flow  for  each  1000  acres 
of  irrigated  land  for  the  Poudre  district;  for  the  Upper  Platte 
district  i  cubic  foot  for  each  430  acres,  and  in  the  Lower  Platte 
the  same  amount  of  return  water  for  each  250  acres,  or  corre- 
sponding amounts  expressed  in  another  unit  of  measure  of  414,- 
720,  964,480,  and  1,658,880  gallons  per  day  per  square  mile, 
respectively.  The  difference,  Professor  Carpenter  states,  "is  due 
mostly  to  the  greater  distance  for  the  seepage  to  reach  the  main 
stream,  and  to  the  times  and  amount  of  water  applied."  It 
has  taken  many  years  for  the  seepage  water  from  irrigated  dis- 
tricts to  fill  the  underground  storage  reservoirs  and  correspond- 
ingly to  raise  the  water-table  sufficiently  to  produce  the  above- 


GROUND-WATER  SUPPLY.  45 

stated  underflow  into  the  rivers,  and  doubtless  an  equilibrium 
is  not  yet  altogether  established.  In  some  instances  the  water- 
table  has  been  raised  forty  feet  or  more. 

It  is  impossible  to  tabulate  the  underground  run-off  per  unit 
of  area  to  serve  as  a  guide  in  estimating  ground-water  yield 
except  in  particular  cases  and  for  local  guidance  only.  In  some 
instances  where  the  collecting  area  is  large  and  flat  and  the  soil 
is  permeable  in  a  rather  humid  climate,  about  30  per  cent  of  a 
minimum  annual  rainfall  and  50  per  cent  of  the  maximum  annual 
rainfall,  or  about  40  to  45  per  cent  of  the  average  annual  rain- 
fall, is  considered  to  be  a  safe  basis  of  estimate.  The  average 
rainfall  is  perhaps  a  safe  basis  of  estimate  where  there  is  exten- 
sive underground  storage  for  the  reason  that  this  storage  can  be 
drawn  upon  for  deficiency  of  yield  during  the  periods  of  abnor- 
mally low  rainfall.  Thus  for  an  average  rainfall  of  38  inches 
covering  a  period  of  50  years  of  record,  40  per  cent,  or  15  inches, 
may  be  considered  available  underground  run-off,  amounting 
to  an  average  daily  yield  of  about  716,000  gallons  per  day  per 
square  mile. 

In  order  that  this  volume  of  water  may  pass  away  freely 
without  water-logging  the  surface  soil,  there  must  be  a  suffi- 
cient depth  of  porous  gravel  formation  beneath  to  admit  of  free 
lateral  movement  of  the  water  and  a  free  outlet.  Thus  upon 
the  assumption  that  the  body  of  moving  water  must  pass  through 
a  layer  of  sand  one  mile  long  we  find  by  computation,  allowing 
one-third  the  volume  of  sand  to  be  void  space,  that  in  order  to 
discharge  716,000  gallons  per  day  the  sand  layer  should  be  at 
least  54  feet  thick  for  a  velocity  through  the  sand  of  i  foot  per 
day,  27  feet  for  a  velocity  of  2  feet,  about  18  feet  for  a  velocity 
of  3  feet,  etc.,  requiring  respectively  a  water-table  slope  for  a 
No.  50  sand,  which  is  an  average  water-bearing  sand,  of  8,  16, 
and  24  inches,  respectively,  per  1000  feet.  But  in  a  very  expan- 
sive flat  valley  where  there  is  little  opportunity  for  surface  run- 
off, also  where  there  is  only  a  comparatively  thin  layer  of 
water-bearing  sand,  say  18  to  20  feet  in  depth,  the  slope  of  the 
water-table  must  necessarily  be  comparatively  light,  in  fact  so 
light  that  a  water-logged  soil  would  result  were  the  underlying 
sand  no  coarser  than  the  No.  50,  which  has  been  assumed.  The 


46  WATER-SUPPLIES. 

heavier  slopes  above  computed  could  only  obtain  in  localities 
where  there  is  corresponding  ground-surface  slopes,  as  in  the  sandy 
coast  territory. 

These  examples  serve  to  illustrate  the  relation  of  the  vari- 
ous factors  which  it  is  necessary  to  consider  in  estimating  ground- 
water  yield  with  a  reasonable  degree  of  accuracy.  But  the  matter 
may  be  carried  a  step  further,  and  the  relation  of  these  several 
factors  with  the  length  of  development  required  in  order  to  col- 
lect the  ground-water  may  be  shown  in  the  form  of  a  diagram 
as  in  Plate  V  on  opposite  page. 

The  diagram  contains  lines  of  slope  for  various  grades  of 
sand,  a  line  of  velocity  in  terms  of  the  voids  in  the  sand  assumed 
to  be  practically  one-fourth  of  the  volume  of  sand,  and  a  curve 
of  length  of  development  required  to  furnish  1,000,000  gallons 
of  water  per  day  for  stated  rates  of  yield  per  lineal  foot  of  devel- 
opment from  a  sand  stratum  35  feet  in  depth  measured  from 
the  water-table  downward.  The  35  feet  of  depth  of  saturated 
sand  is  purely  an  arbitrary  depth  and  is  considered  simply 
because  it  is  the  actual  minimum  depth  of  a  saturated  gravel 
in  the  particular  case  for  which  the  diagram  was  originally  pre- 
pared. In  the  diagram  the  line  of  water-supply  development  is 
assumed  to  have  a  positive  feed  from  both  sides,  hence  the  stated 
rate  of  yield  is  double  the  yield  from  one  side  only.  The  ap- 
plication of  the  diagram  is  readily  understood.  Having  made 
a  boring  on  the  site  of  a  proposed  water-supply  development 
and  by  several  analyses  determined  that  the  average  effective 
size  of  the  water-bearing  sand  is  No.  40,  and  by  levels  of 
the  water  surface  of  various  convenient  wells  in  the  vicinity, 
either  bored  for  the  purpose  or  domestic  wells  in  an  undisturbed 
state,  having  found  that  the  water-table  has  a  slope  of  i  foot 
in  1000  feet,  we  start  at  the  i-foot  mark  on  the  slope  scale 
of  the  diagram,  move  horizontally  across  the  diagram  to  an 
intersection  with  the  slope  line  of  a  No.  40  sand,  then  trace 
vertically  the  line  of  intersection  with  the  length  of  develop- 
ment curve,  then  horizontally  from  that  point  of  intersection 
to  the  development  scale  and  read  the  length  there  indicated; 
the  same  vertical  line  carried  to  the  velocity  line,  then  to  velocity 
scale,  will  give  the  velocity  of  flow  in  terms  of  voids  in  the  sand, 


Scale  of  Ground  Water  Slope  in  Feet  per  1000  Feet. 

»  to  co 


Scale  of  Length  of  Developm  ml  in  Feet  to'Y 


Scale  of  Velocity  in  Feet  per  Day 


4  8  IV A  TER-SUPPL1ES. 

and  also  if  carried  to  the  bottom  of  the  diagram  will  give  the 
yielding  capacity  of  the  sand  from  two  sides  per  lineal  foot  of  de- 
velopment for  the  stated  depth  of  35  feet.  Should  the  depth  of 
water-bearing  sand  be  either  more  or  less  than  the  assumed  35  feet 
of  depth,  the  yield  of  water  per  lineal  foot  of  development  as  as- 
certained from  the  diagram  in  the  manner  above  described  should 
be  multiplied  by  the  ratio  of  the  actual  depth  to  35  and  the  point 
of  the  development  curve  vertically  above  the  corrected  yield  per 
lineal  foot  will  then  give  the  desired  length  of  development.  In 
other  words,  the  yielding  capacity  of  the  sand  is  thus  approxi- 
mated, but  whether  the  actual  feed  is  sufficient  to  support  such 
a  yield  is  a  question  which  must  be  determined  by  a  survey  of 
the  catchment  area  and  examination  of  the  porosity  of  the  sur- 
face soil. 

The  use  of  the  diagram  and  other  data  herein  given  is  designed 
as  a  guide  to  the  judgment  in  estimating  the  yielding  capacity 
of  a  territory  selected  as  a  suitable  site  for  a  ground-water  supply. 
Of  course  where  supply  works  are  already  developed  and  in  use 
for  several  years  the  yielding  capacity  of  the  sand-bed  and  its 
supplying  territory  is  measured  by  the  amount  of  water  actually 
pumped.  There  is  no  adequate  substitute  for  such  a  positive 
test,  provided  the  mechanical  means  of  taking  the  water  out  of  the 
sand  is  in  nowise  throttled,  and  provided  the  physical  data  bearing 
upon  the  effect  of  the  pumping  upon  the  ground-water  table  are 
collected  and  carefully  studied.  In  the  absence  of  such  infor- 
mation there  is  no  way  of  testing  the  full  yielding  capacity  of 
the  supplying  territory  until  the  rate  of  pumping  shall  have 
progressively  increased  up  to  the  breaking-point,  or  that  of 
absolute  refusal  of  the  ground  to  deliver  the  water  in  the  vol- 
ume required  by  the  pumps.  This  experience  often  puzzles  a 
water-works  management  and  may  lead  to  a  dilemma  if  tech- 
nical studies  have  not  been  pursued  in  anticipation  of  a  demand 
for  extensions  and  improvements. 

The  development  of  ground-water  is  accomplished  in  vari- 
ous ways,  but  the  simplest  way  is  probably  the  single  open  well. 
Of  this  method  there  is  little  to  be  said  because  of  its  simplicity, 
except  that  it  is  the  method  often  adopted  by  small  towns  and 
occasionally  under  exceptionally  favorable  circumstances  by 


GROUND  WATER  SUPPLY.  49 

cities  of  considerable  size.  The  open  well  sometimes  serves  the 
triple  purpose  of  storage-well,  receiving-well  for  galleries  or  a 
gang  of  tubular  wells,  as  well  as  for  individual  water-supply  pur- 
poses. An  example  of  this  kind  is  illustrated  in  Plate  VI,  which 
shows  a  small  open  well  receiving  the  siphon  pipes  from  two 
lines  of  tubular  wells.  The  development  lay  at  the  foot  of  a 
hill  bordering  a  piece  of  swampy  ground  supplied  by  springs 
and  was  projected  with  a  view  of  intercepting  the  underflow 
feeding  the  springs  referred  to.  The  supply  of  water  afforded 
by  the  wells  was  small,  about  100,000  gallons  per  day,  but  suffi- 
cient at  the  time  for  the  supply  of  the  village  for  which  it  was 
developed. 

Wells  of  this  kind,  when  penetrating  deeply  a  heavy  and  exten- 
sive bed  of  water-bearing  gravel,  supply  water  in  large  quanti- 
ties, but  may  become  rather  expensive  disappointments  when 
they  simply  uncover  a  thin  layer  of  sand  or  penetrate  what 
may  be  termed  a  pocket  of  gravel.  In  the  one  instance  the 
depth  of  supplying  sand  is  too  small  to  admit  of  either  a  suffi- 
cient storage  or  a  flow  of  water;  in  the  other  instance  the  pocket 
of  gravel  yields  water  bountifully  at  first,  but  finally  fails  as  the 
stored  rainfall  representing  perhaps  years  of  accumulation  becomes 
depleted.  A  case  to  the  point  is  an  open  well  30  feet  in  diam- 
eter and  40  feet  deep  which  uncovered  a  thin  layer  of  sand  about 
3  feet  deep  under  a  deep  heavy  soil.  The  capacity  of  the  well 
was  but  126,000  gallons  per  day  even  when  reinforced  by  two 
6-inch  holes  drilled  into  sand  rock  underlying  the  bed  of  sand. 
In  several  other  instances  wells  30  to  50  feet  in  diameter  com- 
pletely failed  within  a  year  because  of  either  an  insufficient  sup- 
plying area  or  an  exhaustion  of  a  sand-pocket,  notwithstanding 
the  fact  that  a  short-time  pumping  test  developed  the  presence 
of  considerable  water.  Failures  of  this  kind  are  frequent  with 
small  water-works,  but  with  some  degree  of  justification  when 
insufficient  funds  do  not  admit  of  seeking  and  developing  a  more 
distant  but  more  permanent  source  of  water-supply. 

Similar  in  character  and  almost  as  simple  as  the  open  well 
is  the  filter-gallery  which  parallels  a  stream  for  the  purpose  of 
intercepting  and  collecting  the  underflow  through  a  body  of 
gravel.  Like  the  open  well  the  exposed  gravel  bottom  of  the 


GROUND-WATER  SUPPLY.  51 

gallery  furnishes  the  supply  of  water  which  is  delivered  into  a 
receiving- well  within  convenient  reach  of  pumps  or  into  a  gravity 
pipe  connecting  with  some  distant  reservoir.  Galleries  of  the 
latter  kind  connected  with  a  reservoir  of  large  capacity  may 
run  continuously,  but  should  the  rate  of  discharge  exceed  the 
rate  of  underflow  replenishment  a  gradual  depletion  of  ground 
storage  must  ensue  and  eventually  a  gradual  reduction  of  yield 
must  follow.  The  reason  of  this  is  plain  when  it  is  considered  that 
the  maximum  head  or  pressure  of  water  actuating  the  delivery 
into  the  gallery  depends  upon  the  depth  of  the  gallery  below 
the  water-table  and  the  delivery  depends  upon  the  porosity  of 
the  gravel.  Whenever  a  continuous  discharge  from  the  gallery 
causes  the  water-table  to  fall  progressively,  replenishment  is 
evidently  exceeded,  the  actuating  pressure  falls  and  propor- 
tionately the  rate  of  yield  of  the  gallery  decreases  until  an  equi- 
librium between  replenishment  and  yield  is  established. 

A  comparatively  thin  bed  of  coarse  sand  and  gravel  not  far 
from  the  surface  of  the  ground  is  the  most  favorable  condition 
for  gallery  development.  The  gallery  should  be  located  as  far 
as  practicable  below  the  water-table  in  order  to  utilize  to  the 
fullest  extent  the  storage  which  a  gravel  deposit  affords  for 
occasional  heavy  draft  of  water. 

El.  110 
xrtSffi 
River 


_  100 

NirurITG"rou"nd"wIt~eTLe"v"eT"" 

—  90 

Clay Substratum —  80 

FIG.  2. 

Fig.  2  illustrates  the  depth  of  a  deposit  of  water-bearing 
gravel  which  has  furnished  the  water-supply  of  a  large-sized 
city  for  over  fifteen  years. 

The  diagram  shows  the  normal  ground-water  table  to  be  about 
18  to  20  feet  above  an  impervious  clay  substratum.  The  water- 
supply  is  coUected  in  a  system  of  galleries  aggregating  2340  feet 
in  length  leading  into  a  combined  water-supply  and  suction 
well  about  47  feet  in  diameter  containing  in  the  aggregate  a  gross 
infiltration  area  of  12,500  square  feet.  At  the  time  of  which  we 
are  speaking,  the  average  daily  consumption  was  nearly  3,000,000 


52 


WA  TER-SUP >  PLIES. 


gallons  per  day  and  infiltration  was  at  the  rate  of  240  gallons  per 
square  foot  of  gross  area  or  about  300  gallons  per  square  foot  of 
net  area.  This  rate  of  infiltration  has  been  increased  fully  60 
per  cent  upon  occasions  requiring  heavy  fire  service. 

A  water-level  test  with  the  gallery  delivering  nearly  3,500,000 
gallons  of  water  showed  a  drop  at  the  gallery  of  3^  feet  below 
normal  water-table  level  and  an  actuating  slope  of  the  ground- 
water  of  about  7  feet  per  1000  feet,  corresponding  to  a  lateral  veloc- 
ity of  approach  of  about  6  feet  of  solid  water  per  day  through  the 
i6J  feet  of  saturated  gravel  near  the  gallery,  assuming  water  to 
be  supplied  equally  from  both  sides  of  the  gallery.  The  average 
coefficient  of  porosity  is  estimated  at  1000  and  the  effective  grade  of 
the  sand  a  No.  36.  We  regret  to  have  no  mechanical  analysis  of 
the  sand,  but  if  the  curve  of  the  water-table  under  draft  be  com- 
pared with  the  Muscatine  curve  as  shown  by  Fig.  3,  the  higher 
resistance  of  the  sand  referred  to  becomes  apparent. 


Heavy  draught  i 


sand 


E      1G 
I— 15 


E — 14 


= — 18 


E — 12 


= — 11 


Ligh 


raught  in  sand  and  Gravel 


-10 


pt.  25 
pt._26 


= 8- 


=       7 


11109S7G543210 

FIG.  3. — Diagram  of  Ground-water  Curves. 

The  level  of  the  bottom  of  the  galleries  ranges  from  8  to  9  feet 
below  the  normal  water-table,  leaving  several  feet  of  ground 
storage  between  the  gallery  and  the  clay  substratum  which  cannot 
be  drawn  upon  in  emergencies.  The  importance  of  making  this 
deeper  storage  available  justifies  the  construction  of  a  gallery 
somewhat  deeper  than  the  original  galleries  whenever  the  demand 


GROUND-WATER  SUPPLY.  53 

for  water-supply  extension  arises.  The  expense  entailed  in  carry- 
ing out  this  work  may  be  comparatively  heavy,  but  nevertheless  not 
so  great  as  that  of  providing  equivalent  emergency  surface  storage, 
which  would  preserve  unimpaired  the  quality  of  the  ground-water. 
Possibly  the  local  conditions  warrant  this  form  of  water-supply 
development  above  others;  at  any  rate  the  success  of  the  original 
galleries  in  supplying  so  large  a  volume  of  water  as  1,000,000,000 
gallons  or  more  annually  must  certainly  inspire  sufficient  local 
confidence  in  the  form  of  construction  as  to  justify  the  preference. 

It  will  be  noted  in  the  preceding  illustration  that  we  have  made 
an  estimate  simply  of  the  lateral  velocity  of  the  flow  of  water 
through  the  sand  as  it  approaches  the  gallery  to  supply  the  draft 
of  water  therefrom,  and  not  of  the  vertical  velocity  of  infiltration 
through  the  gravel  at  the  bottom  of  the  gallery,  for  the  reason  that 
it  is  the  permissible  velocity  of  approach  to  the  gallery  that  governs 
the  rate  of  infiltration.  In  turn  the  velocity  of  approach  is  con- 
trolled by  the  grade  or  porosity  of  the  sand  through  which  the 
water  must  flow  in  approaching  the  gallery. 

So  far  as  we  know  there  is  no  record  of  measurements  taken  to 
ascertain  the  influence  of  the  river  adjoining  the  gallery  upon  the 
yield  of  ground-water,  nor  yet  of  any  examination  or  survey  of 
the  extent  and  general  physical  characteristics  of  the  water-bearing 
gravel  underlying  the  river  valley.  Thus  far  the  large  amount 
of  water  which  has  been  drawn  from  this  gravel-bed  does  not 
appear  to  have  affected  the  general  characteristics  of  the  water- 
table, which  fluctuates  with  the  rise  and  fall  of  the  adjoining  stream. 
It  is  a  case  where  no  interest  dependent  upon  the  source  of  water- 
supply  seems  to  have  suffered  thus  far  from  a  neglect  of  making  a 
thorough  examination  of  the  water-supplying  capabilities  of  this 
particular  locality.  However,  the  importance  of  the  city  and 
the  magnitude  of  the  investment  now  at  stake  in  this  case,  as  well 
as  in  any  other  similar  case,  should  suggest  to  a  prudent  water- 
works management  the  desirability  at  least  of  making  such  ax- 
aminations  as  admit  of  approximating  the  yielding  capacity  of 
the  existing  source  of  water-supply  and  thereby  become  informed 
of  the  probable  limitation  to  be  placed  upon  future  development 
work. 

Theoretically  the  limitation   of  filtering-gallery  extension  is 


54  WATER-SUPPLIES. 

indefinite  so  long  as  due  regard  can  be  given  to  the  hydraulic  con- 
ditions which  are  necessary  to  produce  the  required  flow  of  water 
within  the  gallery  and  to  structural  requirements.  The  rate  of 
infiltration  should  not  be  so  great  as  to  disturb  seriously  the 
sand  underlying  the  usual  ground  floor  of  the  gallery. 

The  depth  of  gallery  construction  below  the  normal  water-table 
possesses  a  very  decided  limitation  from  the  standpoint  of  cost ;  in 
fact  such  construction  is  confined  in  this  particular  direction  within 
such  narrow  limits  that  it  is  seldom  considered  a  feasible  method  of 
water  development  in  localities  where  deep  water-bearing  strata 
prevail,  particularly  when  the  coarse  and  more  desirable  stratum 
is  near  the  bottom  and  much  below  the  water-table.  Even  where 
the  gravel-bed  is  shallow,  as  in  the  preceding  illustration,  the  supe- 
riority of  a  gallery  over  other  forms  of  development  is  often  ques- 
tionable. Upon  this  debatable  point  it  is  thought  that  much  de- 
pends upon  the  mechanical  make-up  of  the  water-bearing  material 
and  upon  the  cost  of  maintenance  of  gallery  construction  com- 
pared with  other  forms  of  construction. 

For  example  consider  what  other  form  of  water-supply  develop- 
ment can  be  substituted  for  an  infiltration  gallery,  in  the  deposit  of 
water-bearing  material  of  which  Fig.  2,  on  page  51,  is  a  sketch. 
Several  large  open  wells  connected  in  series  by  a  gravity-flow  pipe 
and  finally  with  a  pump-suction  well  could  scarcely  prove  an  ade- 
quate substitute  because  the  expense  of  constructing  the  wells  and 
the  connecting  gravity  pipe  lines  would  fully  equal  the  cost  of  a 
gallery  of  equal  yielding  capacity.  This  fact  seems  clear  upon  the 
face  for  the  reason  that  all  the  conditions  affecting  the  yield  and 
the  cost  of  construction  and  maintenance  are  identical  in  the  two 
cases.  But  were  the  series  of  wells  connected  by  a  series  of  siphons 
of  gradually  increasing  capacity  as  the  suction  well  is  approached 
some  saving  in  the  investment  would  result,  although  the  cost  of 
operation  and  maintenance  of  the  water-supply  works  would  be 
somewhat  increased  because  of  the  necessity  of  having  to  provide 
and  maintain  a  means  of  removing  air  from  the  series  of  siphons. 
The  uncertainty  of  a  prompt  response  of  a  series  of  siphons  to  the 
fluctuating  requirements  of  consumption  and  the  inaccessibility 
of  the  several  siphons  would  militate  against  this  method  of 
development  even  at  a  reduced  cost  of  construction. 


GROUND-WATER  SUPPLY. 


55 


A  more  unique  form  of  construction,  shown  by  Fig.  4,  would  be 
to  construct  a  main  siphon  pipe  parallel  with  but  to  one  side  of  the 
series  of  open  wells  and  on  a  continuous  rising  grade  to  the  suction 
well  where  it  should  terminate  in  a  vertical  down-take  pipe  dip- 
ping several  feet  below  low  water  in  the  suction  well  and  capped 


5 

Branch  Pipe 


J 


i 


i 


i 


Main  Siphon' 


PLAN  OF  SERIES  OF  WATER  SUPPLY  WELLS 


€> 


Suction  Well 


..-To  Air  Pump 


ELEVATION 


FIG.  4. 

at  the  top  by  a  large  vacuum-chamber  from  which  entrailed  air 
could  be  exhausted  by  means  of  a  vacuum-pump.  Each  open 
well  should  then  be  connected  with  the  large  siphon  pipe  by  means 
of  a  branch  pipe  of  sufficient  capacity  to  accommodate  the  yield 
of  the  well  in  the  manner  shown  by  Fig.  5. 


SECTION  THROUGH  SUPPLY  WELL 

FIG.  5. 


Supply  Well 


Junction  Well 


FlG.    6. 


The  objections  to  multiple  siphons  in  the  former  arrangement 
of  open  wells  are  altogether  overcome  by  the  arrangement  just 


56  WATER-SUPPLIES. 

described.  There  is  only  one  siphon  and  only  one  point  in  this 
one  siphon  where  there  is  any  possible  chance  of  an  air-lock, 
namely,  at  the  vacuum-chamber  on  or  near  the  down-take  inlet 
to  the  suction  well,  and  then  only  through  neglect  of  the  attendant 
at  the  pumping-station.  The  vacuum  in  the  siphon  pipe  can 
always  be  maintained  and  the  water-supply  works  can  always  be 
in  shape  to  respond  to  any  demand  of  consumption  up  to  the 
supplying  capacity  of  the  wells.  The  only  chance  for  a  break  is 
through  the  exhaustion  of  the  supply  of  water  in  any  one  well 
to  the  extent  of  exposing  the  mouth  of  the  branch  supply  pipe  to  the 
siphon,  but  this  danger  of  a  break  of  the  vacuum  may  be  avoided 
by  a  small  suction  well  sunk  inside  the  supply  well  to  some  depth 
below  the  limit  of  suction  as  indicated  by  Fig.  6. 

This  form  of  construction  usually  requires  less  investment 
in  water-supply  works  than  does  an  infiltration  gallery.  The  water- 
supply  wells  may  be  sunk  with  proper  appliances  by  dredging  the 
material  from  the  inside  as  the  curb  descends  through  its  own  or 
a  superimposed  weight,  thereby  permitting  all  construction  work 
to  be  accomplished  above  the  ground-water  table  with  but 
little  if  any  pumping  for  construction  purposes,  which  is  the  chief 
source  Of  expense  in  the  construction  of  an  infiltration  gallery. 
The  cost  of  operating  and  maintaining  the  well  system  of  sup- 
ply should  be  no  greater  than  that  of  the  gallery  system  of  supply. 
Besides  a  series  of  wells  can  be  more  readily  sunk  to  a  depth  which 
will  make  available  practically  all  of  the  permanent  storage 
in  the  water-bearing  material,  as  would  be  the  case  in  the  illus- 
tration referred  to  were  the  shoe  of  each  of  the  supply  wells  to 
penetrate  the  water-bearing  material  to  a  level  4  or  5  feet  above 
the  clay  substratum. 

The  general  arrangement  would  perhaps  appear  more  balanced 
were  the  supply  wells  distributed  on  either  side  of  the  siphon  pipe, 
even  though  in  the  matter  of  yield  there  might  be  no  material 
difference,  the  wells  being  naturally  distributed  in  a  direction 
normal  to  the  slope  of  the  natural  ground-water  table. 

Consideration  of  the  matter  of  an  economical  substitute  for  an 
infiltration  gallery  may  be  carried  a  step  farther  by  attempting 
to  find  a  satisfactory  substitute  for  the  large  open  well.  This  step 
naturally  leads  to  a  consideration  of  a  series  of  small  tubular 


GROUND-WATER  SUPPLY. 


57 


wells  ranged  along  either  side  of  the  large  siphon  pipe  which  has 
just  been  described.  These  small  wells  may  be  either  open  or 
closed,  driven  or  bored,  according  to  present  practice.  Imagine 
two  rows  of  small  wells,  one  on  either  side  of  the  siphon  pipe  above 
described  and  close  enough  together  to  absorb  the  entire  flow  of 
water  that  the  water-bearing  material  is  capable  of  passing  at  the 
maximum  permissible  slope.  For  the  purpose  of  ascertaining  what 
the  slope  should  be  to  produce  a  maximum  discharge,  or,  in  other 
words,  for  the  purpose  of  defining  the  limit  to  which  the  water- 
table  should  be  depressed  near  such  a  system  of  wells  as  has  been 
described  in  order  to  produce  a  maximum  velocity  of  approach 
through  the  sand  and  accordingly  a  maximum  discharge,  refer- 
ence is  made  to  Fig.  7  and  the  following  solution. 


FIG.  7. 


Let  v  =  velocity  of  approach  of  the  ground- water  =fo'; 

h-x 
i  =the  slope  of  ground-water  =  — y— ; 

h  =the  depth  from  the  natural  water-table  to  substratum; 

x  =  "  "       "    draft 

/=the   distance   from  wells  to   the  point   where    the    draft 

water-table  meets  the  natural  water-table; 
a  =area  of  saturated  section  at  or  near  the  wells  =x  times  unity 

for  a  unit  length  of  section; 
<2  =  the  discharge  for  24  hours  =av\ 

hence  Q=av  =aki  =xki  for  unit  length  of  section. 


58  WATER-SUPPLIES. 

h-X 
Substitute  in  value  for  Q  the  value  of  i=  —  -,  —  » 

k 
then  Q=jx(h-x). 

Now  the  condition  which  makes  the  factor  x(  h—  x)  a  maximum 
is  the  condition  which  gives  a  maximum  value  for  Q  and  accordingly 
a  maximum  velocity  of  approach  through  the  sand.  It  is  found 
that  the  value  of  x  which  makes  this  factor  a  maximum  is  \h. 

Hence,  by  substitution, 

k  Ik 

Q  =  -(h  —%h)%h  =-r  jh2  in  cubic  feet  per  day. 


In  order  to  reduce  to  a  discharge  in  gallons  per  24  hours,  con- 
sidering the  water  to  approach  equally  from  both  sides  of  a  system 
of  wells,  multiply  the  above  equation  by  2  and  7.5,  making 

0-3.757**. 

Reference  has  been  made  to  an  illustration,  Fig.  2,  where  h  =20 
feet  and  k  =  1000,  and  where  the  observed  value  of  /  was  about 
500  feet;  hence  for  that  case 

3.75X1000X20X20 
Q  =—    -  =3000  gallons  per  day. 

That  is  to  say  this  computed  rate  of  discharge  is  the  maximum  dis- 
charging capacity  of  the  stated  grade  of  sand  under  stated  con- 
ditions of  slope  and  depth  of  water-bearing  material  independent 
of  any  question  of  rainfall  or  river  support,  and  is  representative 
of  the  conditions  which  make  the  best  use  of  the  available  ground 
storage  for  emergency  draft. 

It  is  evident  that  a  gallery  which  is  sufficiently  low  in  the 
ground  to  depress  the  natural  water-table  over  it  one-half  the 
depth  of  the  water-bearing  stratum  receives  the  maximum  rate 
of  infiltration.  But  when  a  system  of  wells  is  substituted  for 
a  gallery,  the  direct  current  of  approach  must  break  up  into  a 


GROUHD-WA7ER  SUPPLY.  59 

series  of  converging  currents  of  rapidly  increasing  velocity  as 
each  well  of  the  series  is  approached.  The  larger  the  number 
of  the  wells  in  a  given  distance  the  less  becomes  the  several  indi- 
vidual areas  of  converging  flow,  until  finally  with  the  small  wells 
practically  in  contact  the  gallery  conditions  become  duplicated 
in  effect.  When  the  wells  are  a  considerable  distance  apart,  as 
they  usually  are,  the  quantity  of  water  entering  the  strainer 
of  any  individual  well  must  equal  the  quantity  which  approaches 
it  by  direct  flow  and  feeds  the  zone  of  the  converging  current 
which  feeds  the  well,  consequently  the  quantity  of  water  flowing 
in  a  prism  of  a  length  equal  to  the  distance  between  the  wells 
and  a  depth  equal  to  one-half  the  normally  saturated  area  divided 
by  the  exterior  area  of  the  strainer  gives  the  velocity  of  flow 
from  the  sand  in  contact  with  the  strainer  subject  to  such  cor- 
rection as  the  relatively  small  area  of  the  strainer  openings  and 
well  interference  may  require. 

Strainers.  —  The  ordinary  well-strainer  possesses  but  about 
13  to  15  per  cent  of  the  entire  metal  surface  as  openings,  and  not 
more  than  one-third  of  this  per  cent  is  available  for  use,  con- 
sequently the  velocity  of  flow  through  the  openings  must  be 
very  much  more  than  the  velocity  of  flow  through  the  sand  at 
the  surface  of  contact  of  the  sand  with  the  strainer. 

There  are  certainly  some  well-defined  principles  upon  which 
the  area  of  the  openings  in,  and  the  length  of,  a  strainer  should 
be  based. 

Evidently  the  openings  should  have  a  form  which  offers  the 
least  resistance  to  the  flow  of  water  and  a  size  which  can  absorb 
the  water  as  fast  as  it  is  delivered  from  the  surrounding  sand. 
Of  course  the  geometrical  form  of  opening  which  offers  the  least 
resistance  to  the  flow  of  water  is  the  circle.  But  while  practical 
considerations  sometimes  require  a  departure  from  the  circular 
form  of  opening  they  do  not  require  a  proportionate  departure 
from  the  effective  discharging  capacity  of  that  form  of  opening; 
for  instance,  a  departure  from  a  circular  to  a  narrow  rectangular 
•opening  should  be  accompanied  with  a  compensating  increase 
of  area  of  the  slot  in  proportion  to  its  greater  resistance  to  the 
flow  of  water. 

Usually  the  head  or  pressure  which  actuates  the  flow  of  water 


60  WATER-SUPPLIES. 

through  the  strainer  opening  into  the  well  is  the  negative  head 
produced  by  pumping.  Whenever  water  does  not  enter  the  well 
fast  enough  through  strainer  openings  of  insufficient  area  the 
pump  gradually  increases  the  vacuum  in  the  well,  within  prac- 
tical limits  of  course,  in  an  effort  to  secure  a  feed  of  water. 
The  resulting  but  gradually  increasing  pressure  outside  the 
strainer  eventually  packs  the  sand  about  the  strainer  to  the 
extent  of  throttling  the  already  deficient  area  of  openings  and 
proportionately  the  feeding  capacity  of  the  strainer.  A  system 
of  wells  thus  throttled  will  usually  be  found  to  yield  a  gradually 
decreasing  volume  of  water  and  finally  to  decrease  the  feed  to  the 
pumps  to  such  an  extent  as  to  render  the  method  of  water- 
supply  development  more  or  less  of  a  failure. 

This  throttled  condition  of  strainer  is  often  the  direct  result 
of  the  use  of  a  strainer  with  openings  so  small  that  the  fine 
sand  cannot  enter  the  well.  The  theory  forming  the  basis  of 
this  practice  may  be  correct  when  the  sand  in  which  the  strainer 
is  embedded  is  generally  fine  and  of  uniform  texture,  but  it  can- 
not hold  good  where  the  layer  of  sand  is  an  assorted  mixture 
in  which  fine  sand  is  a  comparatively  small  percentage  of  the 
bulk,  for  in  that  case  the  strainer  should  be  coarse  enough  to  allow 
the  finer  sand  to  pass  through  the  openings  into  the  well  and  to 
be  removed  mechanically.  In  fact  it  is  often  a  most  excellent 
practice  to  give  each  well  a  preliminary  washing  by  means  of  a 
directly  attached  pump  operated  at  a  rate  of  pumping  some- 
what in  excess  of  that  which  would  prevail  in  general  service. 
Any  portion  of  the  sand  thus  drawn  through  the  openings  of 
the  strainer  and  not  ejected'  from  the  pump  with  the  water 
can  readily  be  withdrawn  with  a  sand-bucket.  The  remnant 
of  coarse  sand  about  the  strainer  prevents  the  subsequent  ad- 
vance of  fine  sand  in  the  same  manner  that  the  graduated  gravel 
layer  of  a  sand-filter  prevents  sand  entering  the  underdrain. 

The  danger  of  further  movement  of  fine  sand  after  such  a 
washing  is  very  remote  because  of  the  rapidly  decreasing  velocity 
of  flow  through  the  sand  as  the  distance  from  the  center  of 
the  well  increases.  In  order  to  determine  what  this  velocity 
may  be  and  the  law  by  which  it  increases  as  the  well  is  approached 
it  is  necessary  to  devise  a  mathematical  expression  embracing; 


GROUND-WATER  SUPPLY. 


61 


the  law  or  principle  of  radial  flow.  Assume  that  the  water  flows 
in  a  radial  direction  towards  the  well  through  a  series  of  con- 
centric cylinders  C,  Ci,  C2  .  . .  W  (Fig.  8)  of  a  depth  x,  Xi,  x2  . .  .  #„,, 
measured  from  the  impervious  stratum  YY  to  the  water-table 
assumed  by  the  approaching  water.  Throughout  each  concen- 
tric cylinder  the  velocity  and  velocity  head  are  constant  and 
are  inversely  proportional  to  the  distance  from  the  center  of  the 
well.  Moreover,  the  velocity  through  any  cylinder  C  multiplied 


FIG.  8. 

by  its  distance  from  the  center  of  the  well  is  equal  to  the  velocity 
of  flow  through  any  other  section  C  multiplied  by  its  distance 
from  the  center.  Hence  by  representing  the  law  of  variation 
of  velocity  by  the  general  formula  p'dv=v'dp=vp=  constant  (c), 
where  p  equals  any  distance  from  the  center,  the  following  gen- 
eral formula  may  be  written: 


c 

v=—. 
P 


(i) 


6  2  W  A  TER-SUPPLIES  . 

It  is  also  known  that  the  quantity  of  water  which  flows 
through  any  cylinder  C  must  also  flow  through  any  other  cylinder 
Ci,  €2- 

In  the  general  expression  for  velocity  v  =ki,  where  k  =the 
factor  of  resistance  and  i  is  the  slope  which  for  any  in- 
finitely small  arc  of  the  curved  water-table  of  radial  flow  may 

be  expressed  by  -         Hence 


By  substituting  the  value  of  v  of  equation  (i)  in  equation  (2) 
there  follows: 

c      ,dx  dp 

_=£—    or    c—=kdxy 
p       dp  p 

or 

(3) 


Now  if  the  distance  from  the  well  to  the  boundary  where 
the  water-table  of  approach  to  the  well  meets  or  becomes  the 
natural  water-table  be  represented  by  R  with  its  corresponding 
value  of  x=h,  the  natural  depth  of  the  water-bearing  material, 
and  the  distance  from  the  center  to  the  exterior  of  the  well  by  r, 
where  the  value  of  x  =x,  we  may  substitute  these  values  in  equa- 
tion (3)  and  solve  for  C.  Hence 


c\oger  —  kx  =C. 

Now  placing  the  values  of  C  equal  to  each  other  there  follows: 
cpog,  (R+r)  -log,  r]  =k(h-x). 
k(h-x) 


i       (R+r\ 
log,  (— ) 


(4) 


*  The  theoretical  portion   of  this  demonstration  is  suggested  by  Prof.  Slichter's 
analysis  of  radial  flow  in  Nineteenth  Annual  Report  of  U-  S.  Geological  Survey. 


GROUND -WATER  SUPPLY.  63 

Substituting  the  value  of  c  of  equation   (4)  in  equation   (i) 
an  expression  for  velocity  is  found: 


For  the  particular  case  of  velocity  or  discharge  at  the  cir- 
cumference of  the  well  let  p=r  and  Q=av=2nrxv,  and  by  sub- 
stitution in  equation  (5)  an  expression  for  discharge  follows: 

-x) 


log, 

Since  the  expression  for  Q  is  in  terms  of  the  variable  x  in 
the  term  x(h-x),  there  is  some  value  of  x  which  makes  this  term 
and  consequently  Q  a  maximum. 

Let  u=x(h— x), 
then     du  =  hdx  —  2xdx. 

du 

•j—=h-2x=o    or    x=±h. 

ax 

d2u 


Hence  the  above  term  and  consequently  equation  (6)  become 

h 

a  maximum  when   =x  —  . 
2 

Now  by  making  this  substitution  in  equation  (6)  and  reducing, 
there  results 


. 

Vmax.  = 


A  similar  substitution  of  x=%h  and  p=r  in  equation  (5) 
gives  a  value  of  velocity  corresponding  to  a  maximum  rate  of 
discharge  at  the  well  circumference  as  follows,  wherein  d=  diam- 
eter of  well: 

kh 


64  WATER-SUPPLIES. 

In  formulae  (4)  to  (8),  inclusive,  the  natural  logarithm  (\oge) 
is  used  and  may  be  found  by  multiplying  the  common  logarithm 
by  2.3.  The  reduction  is  made  in  the  formulae  which  follow 
and  the  logarithm  indicated  by  c.l. 

Formulae  (5)  to  (8),  inclusive,  should  be  multiplied  by  a  factor 
of  resistance  of  flow  from  the  sand  through  the  strainer,  and  so 
far  as  investigations  have  gone  they  point  to  a  range  of  values 
of  0.17  to  0.25.  Accordingly  the  reduced  formulae  become 

kh2 

<?max.  =0.114  tO  O.I7  -  .....         (9) 


=0.073  tO  O.II  --  .       .       .       .       (10) 


For  general  application  formulae   (5)  and   (6)  similarly  cor- 
rected become 

Q=o.45too.68fe   X(k^ (ii) 

V    r    } 

k(h-x) 

V  =0.146  tO  0.22-  .         .      .      .      (12) 


The  above  formulae,  (9)  to  (12),  inclusive,  when  applied  to  the 
flow  into  small  wells  like  the  ordinary  drive  or  tubular  well  may 
be  still  further  abbreviated  without  appreciable  error  by  writing 

for  com.  log.   I j,  com.  log.   (-T),  where  D  =  diameter  of  the 

outer  extremity  of  the  zone  of  depression  and  d=the  diameter 
of  the  well. 

A  still  further  reduction  may  be  made  of  the  formulas  for 
special  application  to  tubular  wells  by  assuming  the  average 
diameter  of  a  tubular  well  to  be  \  of  a  foot  and  that  the  average 
radius  of  the  zone  of  depression  is  1000  feet,  then  the  com.  log. 


GROUND-H/4TER  SUPPLY.  65 

of  2000  -i-J  becomes  equalto  3.6.     Substituting  this  value  in  for- 
mulae (n)  and  (12)  there  results  — 


For  tubular  wells: 


to  °-I9  kx(h—x)  .....     (13) 


^=0.04  to  o.o6i-j(A-#)  ......     (14) 

For  maximum  velocity  let  x=%h. 

(?max.  =0.031  tO  0.0475  M2  .....       (15) 
Fmax.  =0.02  tO  0.03  -j  .......       (l6) 

Precise  results  need  not  be  expected  from  these  or  any  other 
formulae  relating  to  ground-water  flow,  but  they  serve  to  show 
the  relation  of  factors  and  conditions  and  to  aid  the  judgment 
in  the  study  of  ground-water  conditions  and  in  the  design  of 
water-supply  works.  Simple  and  approximate  formulae  serve 
practical  purposes  much  better  than  complex  formulae,  even 
though  the  latter  may  be  more  accurate  theoretically. 

It  should  also  be  remembered  that  when  the  values  k  of  the  table 
on  page  31  or  37  are  used,  together  with  the  values  of  other  unknown 
quantities  expressed  in  feet,  the  result  of  the  solutions  of  the  for- 
mulae are  in  feet  or  cubic  feet  per  day  of  a  solid  column  of  water. 
Considerable  departure  from  the  results  of  these  formulae  may 
be  expected  where  the  material  which  supplies  the  water  to  a 
well  is  fissured,  thereby  admitting  of  the  approach  of  water  through 
channels  of  much  less  resistance  than  the  natural  pores  of  sand 
and  gravel.  Channels  of  this  kind  are  to  be  expected  in  a  rock 
formation  and  are  sometimes  encountered  in  a  gravel  formation. 

It  does  not  necessarily  follow  from  the  discussions  that  the 
length  of  a  strainer  should  be  one-half  the  depth  of  the  water- 
bearing material  in  order  to  take  advantage  of  the  maximum  de- 
livery of  the  sand.  In  some  instances,  as  when  the  water-bearing 
material  is  of  a  uniform  grade  and  not  deep,  and  when  the  great- 
est possible  yield  of  water  is  desired  in  emergencies,  the  stated 
length  of  strainer  may  be  desirable.  In  other  cases  the  strainer 


66  WATER-SUPPLIES. 

may  be  considerably  shorter,  as,  for  instance,  when  it  is  desirable 
to  confine  the  strainer  to  a  coarse  material  underlying  a  compara- 
tively fine  material  and  to  absorb  the  water  in  the  superimposed 
fine  material  through  the  coarse  material.  Thus  while  the  length 
of  the  strainer  need  never  be  more  than  half  of  the  depth  of  the 
water-bearing  material,  it  may  be  considerably  shorter,  depending 
upon  the  relative  porosity  of  the  several  strata  and  upon  the 
support  which  the  yield  of  the  supplying  gravel  receives  from  the 
rainfall  or  other  sources. 

In  every  instance,  however,  the  diameter  of  the  strainer  should 
be  one  which  will  admit  of  perforations  of  a  sufficient  aggregate 
capacity,  within  the  limits  of  the  desired  length,  to  absorb  the 
water  as  fast  as  delivered  from  the  sand  at  its  maximum  rate  of 
flow.  This  statement  is  also  true  of  a  strainer  of  greatest  length 
in  a  water-bearing  material  of  practically  uniform  texture. 

An  approximate  formula  for  the  area  of  strainer  openings  may 
be  derived  in  the  following  manner:  Let  the  discharge  through 
a  rectangular  orifice  be  represented  by  the  formula 


Qf  =  (cbd\/2gh')  F,  in  cu.  ft.  per  sec., 

where   c  =a  coefficient  of  resistance  of  discharge  =0.6; 

bd=  aggregate  area  of  strainer  openings; 
\/2g  =  effect  of  gravity  =8; 
h'  =  velocity  head  =h  —  x; 

jp=a  factor  of  reduction  to  discharge  per  24  hours  com- 
bined with  a  factor  to  cover  blank  space  between  slots  and  the 
reduction  of  area  of  slots  resulting  from  contact  of  sand  and 
gravel  =  (F'F" )  =  TV  X  86400. 

By  substitution  and  reduction, 

Q'  =2j6$bd\/h-x. 

Since  the  radial  flow  at  the  well  must  be  equal  to  the  flow 
through  the  strainers,  we  may  place  Q  of  equation  (13)  equal  to  Q' 
and  solve  for  bd',  hence 


—  #=0.125  to  0.19  kx(h—x), 
or          6^  =  0.00065  too. oo i  kx\/h—x,  in  square  inches,  .     .     (17) 
or  (&d)max.  =0.00016  to  0.00025  kh*/2h,  in  square  inches.     .     (18) 


GROUND-WATER  SUPPLY.  67 

It  should  be  observed  that  fine  strainer  openings  possess  a 
very  low  value  of  area  and  hydraulic  mean  depth  and  conse- 
quently a  very  low  discharging  capacity;  for  instance,  the  ordi- 
nary horizontally  slotted  strainer  having  slots  i£  inches  long  by  & 
of  an  inch  wide  has  an  area  of  about  fa  of  a  square  inch  and  a 
hydraulic  mean  depth  of  about  0.015  and  a  total  area  of  nearly 
3^  square  inches  per  lineal  foot  of  each  row  of  slots;  the  hydraulic 
mean  depth  of  a  vertical  slot  12"  high  and  J  of  an  inch  wide  is 
about  0.125  or  nearly  eight  times  that  of  the  small  slot  and  the 
area  3  square  inches.  Since  the  discharge  varies  as  the  square  root 
of  the  hydraulic  mean  depth,  the  relative  hydraulic  efficiency  of  the 
two  slots  is  at  least  one  to  two  and  one-half  in  favor  of  the  coarse 
slot. 

Rock  wells,  or  those  which  are  formed  by  drilling  into  a  water- 
bearing rock,  are  subject  to  the  application  of  the  principles  of 
flow  herein  discussed  when  the  rock  formation  is  porous  rather 
than  fissured.  As  a  rule  the  drill-hole  in  the  rock  is  not  cased  any 
deeper  than  is  necessary  to  get  a  proper  location  for  a  pump,  if 
conditions  require  the  use  of  a  deep-well  pump.  The  strainer 
is  the  exposed  portion  of  the  drill-hole  extending  below  the  casing 
and  possessing  a  yielding  capacity  dependent  upon  its  porosity  and 
within  limits  upon  the  amount  the  water-table  is  depressed  by 
pumping  and  upon  the  depth  of  penetration  of  the  drill-hole  into 
the  water-bearing  rock. 

The  yield  of  a  rock  well  varies  so  slightly  with  an  increase  of 
diameter,  as  indicated  by  the  formulae  on  the  preceding  pages, 
that  the  diameter  of  the  well  is  an  insignificant  factor  in  the  ques- 
tion of  yielding  capacity.  To  what  extent  the  seams  and  fissures 
facilitate  the  flow  of  water  through  a  rock  formation  is  purely 
problematical,  but  so  far  as  observation  goes  they  are  numerous 
even  in  sandstone  strata  and  constitute  the  principal  avenues 
of  flow.  In  one  instance  which  comes  to  mind,  a  water- 
supply  well  8  feet  in  diameter  excavated  through  a  dry  shale 
uncovered  at  a  depth  of  125  feet  a  stratum  of  water-bearing 
sandstone  in  which  the  pressure  was  sufficient  to  carry  the  water 
vertically  10  feet  above  the  top  of  the  stratum.  The  well  pene- 
trated the  sand  rock  25  feet  and  was  then  bowled  out  to  a  diameter 
of  about  20  feet.  The  water  entered  the  well  through  seams  and 


68  WATER-SUPPLIES. 

crevices  and  freely  through  a  1 2-inch  bore-hole  penetrating  12 
feet  below  the  bottom.  The  yield  of  the  well  was  never  accu- 
rately measured,  but  was  approximately  60,000  to  70,000  gallons 
per  day,  and  after  a  short  period  of  time  seemed  to  come  chiefly 
through  seams,  fissures,  and  drill-holes  in  or  near  the  bottom,  the 
sides  of  the  well  becoming  quite  thoroughly  drained.  Similar 
conditions  of  flow  were  observed  in  other  wells  and  in  a  tunnel  cut 
through  sand  rock.  The  physical  conditions  surrounding  the  flow 
of  subterranean  water  through  rock  are  found  to  be  more  complex 
than  those  governing  the  flow  of  water  through  sand  and  gravel 
deposits,  and  accordingly  wider  departures  of  the  actual  yield  of 
water  from  wells,  theoretically  computed  from  formulae,  may  be 
expected.  However,  there  appears  no  good  reason  for  the  modifi- 
cation of  the  formulae  hereinbefore  offered,  at  least  in  the  general 
form,  although  the  constants  and  relation  of  factors  may  be  altered 
to  suit  localities  where  investigation  has  developed  the  con- 
trolling physical  conditions. 

This  line  of  discussion  might  be  pursued  further  were  it  not  for 
the  fact  that  rock  wells  are  not  the  usual  form  of  ground-water 
supply  development  except  in  a  comparatively  few  favored  local- 
ities where  heavy  artesian  flow  is  available.  Moreover,  the  expense 
of  developing  large  quantities  of  water  from  rock  formation  sup- 
plying only  non-flowing  wells  is  heavy  per  unit  of  volume  of  water 
thus  developed — in  fact  very  much  heavier  than  is  the  cost  of 
developing  an  equal  flow  of  water  from  sand  and  gravel  deposits, 
and  often  greater  than  the  cost  of  the  purification  works  required 
to  purify  an  equal  amount  of  surface-water. 

Returning  to  the  subject  of  well-strainer,  it  may  be  stated  that 
the  form  of  strainer  is  an  essential  consideration  in  the  develop- 
ment of  ground-water  supply  and  can  in  nowise  be  restricted 
to  any  particular  standard  of  manufacture.  The  ordinary  drive- 
well  strainer,  composed  of  a  metal  skeleton  surrounded  with  wire 
gauze  and  a  perforated  sheath  of  brass  plate,  is  sometimes  in- 
jured seriously  in  driving  and  is  altogether  unsuited  to  a  coarse 
water-bearing  bed  of  sand  and  gravel.  This  form  of  strainer  is 
usually  employed  for  wells  of  2  to  3  inches  in  diameter,  and  in  this 
regard  is  open  to  the  serious  objection  of  being  forced  out  of  a 
vertical  direction  by  an  obstacle  like  a  stone  or  buried  log  of  wood; 


GROUND-WATER  SUPPLY.  69 

in  fact  any  form  of  drive-point  strainer  leaves  one  entirely  in 
the  dark  as  to  the  precise  character  of  the  material  encountered  in 
driving  and  accordingly  without  any  knowledge  whatever  of  the 
most  suitable  stratum  in  which  to  imbed  the  strainer.  While  the 
use  of  it  serves  a  good  purpose  for  the  development  of  a  small 
amount  of  water  for  individual  uses,  still  there  is  scarcely  any 
warrant  for  its  application  to  the  development  of  water  for  the 
public  water-supply.  What  is  needed  in  this  regard  is  a  form 
of  strainer  designed  to  suit  the  grade  of  material  found  in  the  most 
desirable  substratum  located  by  borings  which  expose  the  location 
and  general  make-up  of  all  the  substrata.  Such  a  strainer  may  fre- 
quently be  reduced  to  the  simple  form  of  a  series  of  vertical  slots 
£  to  f  of  an  inch  wide,  cut  through  an  ordinary  wrought-iron  or  steel 
pipe  jointed  with  the  well-casing  and  an  inseparable  part  thereof. 
The  wide-slot  strainer  can  frequently  be  used  in  material  so  fine 
that  much  of  it  can  pass  through  the  slots  by  simply  depositing  a 
layer  of  gravel  between  the  strainer  and  the  sand  surrounding  it 
during  the  process  of  construction.  This  may  be  accomplished 
by  first  sinking  a  casing  to  the  impervious  substratum  several 
inches  larger  in  diameter  than  the  strainer,  then,  after  lowering 
the  permanent  well-tubing  with  its  attached  strainer  to  the  desired 
position  inside  the  large  tube,  by  filling  beneath  and  around  the 
strainer  with  clean  gravel  too  .large  to  pass  the  slots  (see  Fig.  9). 
Upon  pulling  the  outer  casing  the  layer  of  gravel  remains  between 
the  strainer  and  the  water-bearing  sand  and  has  the  same  relation 
thereto  as  the  surface  layer  of  gravel  of  a  filter  has  to  the  sand 
above  and  the  underdrain  beneath  it.  The  gravel  can  be  de- 
posited about  the  strainer  progressively  as  the  outer  casing  is 
withdrawn  in  order  to  offer  less  resistance  and  thereby  facilitate 
the  work  of  withdrawing  the  outer  casing,  which  at  the  best  is 
heavy  work.  The  construction  shown  by  Fig.  9  is  adapted  to 
deep  water-bearing  strata,  but  a  modified  form  is  practicable  in 
thin  coarse  water-bearing  material  where  for  practical  reasons 
it  is  necesary  to  use  a  short  strainer  of  comparatively  large  diameter. 
Fig.  10  illustrates  this  form  of  strainer  and  represents  a  case  where 
the  drop-pipe  is  attached  at  one  end  to  the  strainer  and  at  the  other 
end  to  a  siphon  or  suction-pipe  under  conditions  where  a  serious 
air  leak  would  be  fatal  to  successful  operation.  The  strainer  must 


7  o  WA  TER-SUPPLIES. 

be  so  short  that  the  depressed  water-table  shall  not  come  below 
the  strainer  openings,  for  the  air  which  enters  the  exposed  slots 
will  destroy  the  vacuum  formed  by  siphon  action  or  by  the  pumps. 
The  strainer  attached  to  the  drop-pipe  through  a  reducing  special 
has  an  open  bottom  resting  on  an  artificially  made  bed  of  heavy 
gravel  and  absorbs  water  through  large  vertical  slots.  It  may 
be  made  of  ordinary  wrought-iron  or  steel  pipe. 

Like  the  previous  case  the  wells  must  be  excavated  through  a 
casing-tube  larger  in  diameter  than  the  strainer,  the  bottom  of 


Strainer 


Casing 


Impervious  Stratum 

FIG.  9. 

gravel  deposited  inside  the  tube,  the  strainer  and  drop-pipe  ad- 
justed to  position,  then  the  outer  casing  must  be  carefully  with- 
drawn. The  bed  of  gravel  should  be  deep  enough  to  allow  of  a 
free  flow  of  water  through  the  open  bottom  of  the  strainer  as  well 
as  through  the  slots. 

When  the  water-bearing  material  is  not  coarse  enough  to  admit 
of  this  form  of  construction  and  is  about  uniform  of  texture,  a  sub- 
stitute may  be  employed,  as  shown  by  Fig.  n.  In  this  instance 
the  casing  with  attached  strainer  plugged  at  the  bottom  is  sunk 
to  the  impervious  substratum  or  to  an  intermediate  position  be- 
neath the  surface  of  the  ground.  A  smaller  drop-pipe  without  per- 


GROUND-WAITER  SUPPLY. 


f orations, but  with  an  open  bottom,  is  made  to  terminate  a  foot  or  so 
above  the  strainer-plug  and  at  the  other  end  to  connect  with  the 
siphon  or  suction-pipe.  The  casing  remains  open  or  loosely 
covered  at  the  top  in  a  manner  to  admit  free  passage  of  air  into  and 
out  of  'the  well-casing.  The  danger  of  an  air  leak  is  entirely 
removed  by  this  arrangement  no  matter  how  much  the  water- 
table  may  be  depressed  below  the  top  of  the  strainer,  provided 
the  bottom  of  the  drop-pipe  retains  its  water  seal.  It  seems 


Water  Level 


Perforated  Casing 


FIG.  TO. 


FIG.  ii. 


unnecessary  to  state  here,  considering  previous  pages  of  this 
chapter,  that  the  strainer  in  this  form  of  well  should  never  ex- 
ceed one-half  the  depth  of  the  water-bearing  material,  and  that 
the  slots  of  the  strainer  should  be  as  coarse  as  it  is  possible  to  use 
in  any  given  water-bearing  material  even  though  it  may  be  neces- 
sary to  subject  the  well  to  a  thorough  preliminary  washing  to 
remove  all  the  fine  sand  about  the  strainer  before  the  well  is  put  in 
commission.  In  fact  the  washing  process  is  in  most  instances  a 
necessary  part  of  the  construction  work  with  any  form  of  strainer 
fitted  for  use  in  a  public  water-supply,  except  in  cases  where  the 
sand  is  decidedly  fine  and  a  very  small  yield  of  water  only  is  ex- 
pected. It  is  always  better  to  have  a  strainer  too  long  than  too 


7  2  WA  TER-SUPPLIES 

short,  and  whenever  a  doubt  arises  as  to  the  danger  of  air  leaks 
through  exposed  strainer  perforations  it  is  better  to  adopt  the 
open-well  construction  shown  in  Fig.  n  rather  than  to  shorten 
the  strainer  unduly. 

Drop-pipes.  The  drop-pipe  connects  the  well  with  the  siphon  or 
suction-pipe  by  two  forms  of  construction  in  the  usual  practice. 
The  one  form  consists  of  a  lateral  extension  of  the  well-casing  to 
the  siphon  or  suction-pipe,  making  the  casing  a  part  and  parcel 
of  the  system  exposed  to  vacuum  conditions  and  practically  a 
closed-well  system  of  construction;  in  the  other  form  of  construc- 
tion, the  open- well  construction,  the  drop-pipe  descends  inside 
the  well-casing  and  is  no  part  thereof.  Figs.  9,  10,  and  n  show 
the  two  forms  of  construction  referred  to.  In  the  latter  form  of 
construction  the  vacuum  affects  the  drop-pipe  only,  the  inside  of 
the  well  being  always  exposed  to  atmospheric  pressure.  The  well 
itself  with  the  same  strainer  capacity  will  yield  practically  the 
same  amount  of  water  under  both  forms  of  construction;  accord- 
ingly the  choice  of  the  method  of  construction  becomes  tech- 
nically a  matter  of  adaptability  to  the  physical  conditions 
surrounding  the  water-bearing  material. 

First  cost  is  always  an  important  factor  of  consideration. 
Where  the  water-bearing  material  is  deep  and  where  the  most  desir- 
able substratum  for  the  strainer-bed  lies  below  the  influence  of  the 
vacuum  effect  of  the  siphon  pipe  the  relative  cost  of  the  two 
methods  of  construction  described  may  be  of  primary  considera- 
tion; but,  on  the  other  hand,  where  the  range  of  vacuum  effect 
extends  to  a  level  below  that  of  the  upper  portion  of  the  strainer, 
the  danger  of  the  admission  of  air  through  the  exposed  openings 
of  the  strainer  renders  the  question  of  first  cost  subordinate  to 
questions  of  a  purely  technical  character  relating  to  the  mechanical 
superiority  of  the  one  form  over  the  other  form  of  construction, 
having  in  view  the  security  of  a  continuous  service.  When- 
ever the  plan  of  water-supply  development  embraces  a  series  of 
wells  connected  with  a  siphon  or  suction  pipe  it  is  perfectly 
apparent  that  all  wells  must  be  equally  responsive  to  vacuum 
effect  if  under  equally  favorable  conditions  of  mechanical  make-up 
each  well  is  expected  to  deliver  its  proportionate  part  of  the  total 
yield  of  water.  In  order  that  this  condition  of  yield  may  prevail 


GROUND-WATER  SUPPLY.  73. 

throughout  the  system,  the  length  and  diameter  of  drop-pipe 
must  be  proportioned  for  equal  resistance  of  a  unit  yield  of 
water.  Just  what  the  measure  of  this  resistance  should  be  is  a 
matter  for  local  determination,  but  as  a  rule  it  should  be  low, 
perhaps  not  more  than  i  or  2  feet  of  total  loss  in  any  drop-pipe. 

The  drop-pipe  should  rise  continuously  to  the  siphon  pipe 
in  order  to  avoid  any  possibility  of  an  air-trap,  and  should  be 
supplied  with  a  stop-valve.  Sometimes  a  check  is  also  added, 
the  object  of  which  is  to  hold  the  water  in  the  siphon  pipe  when- 
ever the  siphon  is  not  in  operation. 

Siphon  Pipe.  The  line  of  pipe  connecting  the  system  of 
wells  is  termed  a  siphon  pipe  when  it  dips  into  an  open  well  from 
which  the  pumps  draw  their  supply  of  water,  and  receives  the 
name  of  suction-pipe  when  it  connects  the  system  of  wells  directly 
with  the  pumps.  In  either  case  the  discharge  head  or  pressure 
producing  the  flow  of  water  from  the  wells  depends  upon  the 
vacuum  formed  by  the  pumps  directly  in  the  suction-pipe,  or 
indirectly  in  the  siphon  pipe  through  the  medium  of  the  open 
well.  Preference  is  usually  given  to  the  siphon  connection  with 
the  wells  particularly  when  a  steady  flow  under  a  high  vacuum 
is  desired,  for  the  reason  that  the  water  in  the  suction-well  feels 
the  pulsation  of  the  pumps  moderately  only,  and  the  pump  effect 
is  communicated  to  the  tubular  wells  to  a  degree  depending 
inversely  upon  the  size  of  the  suction  well  into  which  the  siphon 
discharges  and  from  which  the  pumps  take  the  suction  water. 

The  pipe  line,  whether  acting  as  a  siphon  or  suction  pipe, 
should  be  laid,  when  practicable,  with  a  continuous  and  slightly 
ascending  grade  either  toward  the  well  or  the  pump,  as  the  case 
may  be.  No  form  of  obstruction  should  hinder  the  flow  of  air 
and  gas  from  the  furthermost  water-supply  well  to  a  summit 
from  which  the  air  can  be  taken  out  mechanically.  Comment 
is  scarcely  necessary  to  emphasize  the  care  with  which  the  grade 
should  be  established  and  the  pipe  jointed  into  a  straight 
and  graded  line,  but  a  word  of  caution  is  necessary  judg- 
ing from  the  apparently  careless  manner  in  which  some  work 
of  this  character  has  been  done.  Flange- join  ted  cast-iron  pipe 
is  the  best  material  for  work  of  this  kind,  but  the  expense  its 
use  entails  is  often  prohibitive.  The  best  substitute  is  lead- 


74  WATER-SUPPLIES. 

jointed  cast-iron  pipe  with  a  slab  of  reinforced  concrete  under 
each  joint.  The  slab  of  concrete  should  be  formed  in  the  bot- 
tom of  the  trench  to  conform  nicely  to  the  proper  grade  for  each 
joint  and  each  special  casting,  and  after  the  pipe  is  laid  and 
jointed  it  may  be  found  an  act  of  prudence  well  repaid  to  rigidly 
support  each  pipe  where  it  enters  the  bell  of  its  neighbor  as  a 
provision  against  settlement  or  straining  of  a  joint  when  the 
earth  removed  from  the  trench  is  returned. 

It  is  necessary  to  provide  a  chamber  of  considerable  size  at 
the  point  where  the  siphon  descends  into  the  suction  well.  An 
air-pipe  should  lead  from  the  top  of  this  chamber  to  a  dry  vacuum- 
pump  located  in  a  convenient  place,  preferably  in  the  engine- 
room,  with  which  to  exhaust  the  siphon  of  air  and  gas  accumu- 
lating during  the  operation  of  the  siphon.  The  down-take  pipe 
should  descend  to  a  level  in  the  suction-well  twenty-five  or  more 
feet  below  the  level  of  the  pump.  When  laid  out  in  this  manner 
the  siphon  line  should  be  found,  and  if  the  work  of  design  and 
construction  is  carefully  done,  will  be  found  as  positive  and 
reliable  of  operation  as  any  form  of  construction  that  can  be 
devised. 

The  substitution  of  a  suction-pipe  for  a  siphon  is  scarcely 
warranted  from  a  purely  technical  point  of  view,  although  some- 
times advisable  in  connection  with  a  small  water-works  or  when 


Siphon  Pipe 


i — Air  Trap 


pipe  to  Pumps 
Pipe  to  Pumps 


the  local  substrata  are  of  such  a  character  as  to  entail  unusually 
heavy  expense  in  the  construction  of  a  suction  well  deep  enough 
to  form  the  requisite  vacuum.  In  such  instances  a  vacuum 
chamber  near  the  pumps  is  necessary  and  sometimes  in  addi- 
tion to  the  chamber  an  air-trap  in  the  suction-pipe  similar  to 
that  of  Fig.  12. 

The  pipe  entering  the  trap  from  the  wells  is  a  few  inches 
higher  than  the  pipe  leaving  the  trap  to  connect  with  the  pumps, 


GROUND-WATER  SUPPLY.  75 

The  rising  pipe  of  the  trap  should  be  large  enough  to  admit  of 
easy  circulation  of  water  in  dropping  from  the  inlet  to  the  out- 
let, and  at  the  top  should  have  an  air-pipe  connected  with  a 
dry  vacuum-pump.  If  the  trap  is  large  the  effect  of  pump  pul- 
sation upon  the  well  may  be  greatly  softened. 

Usually  the  line  of  water-supply  development  is  restricted 
to  a  direction  normal  to  the  slope  of  the  water-table.  There- 
fore the  requirements  relating  to  future  extension  should  be 
given  due  consideration  during  the  original  design  and  con- 
struction. Accordingly  it  may  not  always  be  the  part  of  economy 
to  reduce  the  diameter  of  a  siphon  or  suction  pipe  as  it  recedes 
from  the  station  and  finally  to  end  it  in  a  pipe  of  a  capacity  for 
the  flow  of  but  one  or  two  wells.  This  course  of  procedure,  though 
common  with  small  water-works,  is  injudicious,  for  it  defeats  all 
aims  at  economy  when  the  occasion  arises  for  an  extension.  The 
velocity  head  and  frictional  resistance  of  flowing  water  in  either  a 
siphon  or  suction  pipe,  as  well  as  in  the  drop-pipes  of  the  wells 
and  through  the  well-strainers,  are  proportional  to  the  vacuum 
up  to  the  practical  limit  of  20  to  25  feet.  If  for  any  reason  the 
line  of  pipe  connecting  the  system  of  wells  is  too  long  or  of  insuffi- 
cient size  to  admit  of  the  full  flow  of  the  wells  without  increasing 
frictional  resistance  beyond  the  supporting  power  of  the  vacuum 
the  system  becomes  throttled  in  the  proportion  that  the  resist- 
ance of  full  flow  exceeds  the  available  vacuum.  Consequently 
a  constructed  system  of  piping  connecting  a  series  of  wells  which 
in  the  outstart  absorbs  the  head  produced  by  an  available  vacuum 
will  gain  little,  if  any,  by  extensions  of  any  sort.  Therefore  a 
liberal  allowance  of  pipe  capacity  is  essential  even  to  the  extent 
of  a  uniform  diameter  of  siphon  or  suction  pipe  in  anticipation 
simply  of  future  extensions. 

Perhaps  a  diagram  may  make  the  points  more  evident  and 
impressive. 

In  sketch,  Fig.  13,  is  illustrated  a  siphon  connecting  a  series 
of  wells  discharging  into  a  suction  well,  also  the  suction  pipe  from 
the  pumps  entering  the  suction  well.  The  natural  ground- water 
table  is  shown  by  the  higher  of  the  two  broken  lines  and  the 
vacuum  line,  say  20  feet  below  the  center  of  the  pump-plungers, 
by  the  lower  broken  line.  The  air  having  been  exhausted 


76 


WATER-SUPPLIES. 


from  the  siphon  pipe  and  siphon  conditions  having  been  estab- 
lished therein,  the  head  of  water  under  which  the  siphon  works 
is  represented  by  the  difference  of  level  between  the  water  in  the 
suction-well  as  it  is  depressed  by  the  operation  of  the  pumps  and 
the  water  in  the  ground  at  natural  ground-water  level  or  the  head 
BC  +  CD.  This  head  becomes  a  maximum  at  the  lowest  level 
that  the  pumping-engine  is  capable  of  maintaining  the  water  in 
the  well.  The  head  AB  represents  the  lift  of  water  produced  by 
the  vacuum  conditions  from  the  natural  level  of  the  water-table 
to  the  highest  point  of  the  siphon  pipe  and  reduces  to  zero  when 
the  siphon  pipe  is  laid  at  the  level  of  the  natural  ground-water 
table.  This  head  AB  has  no  bearing  upon  the  flow  of  water 


Line  of  Vacuum  20  belowr  Center  of  Pump    D 


FIG.  13. 

through  the  siphon,  for  when  the  water  in  the  well  rises  to  the 
level  of  the  ground-water,  flow  through  the  siphon  ceases  and 
the  head  AB,  which  is  a  negative  head,  simply  holds  the  water 
in  the  pipe  system,  that  is  to  say,  keeps  the  system  primed.  The 
amount  of  this  negative  head  or  lift  that  is  permissible  depends 
upon  the  practical  limit  of  a  siphonic  vacuum,  20  to  25  feet,  and 
upon  the  amount  that  it  is  desirable  to  depress  the  natural  ground- 
water  level.  From  the  standpoint  of  economy  of  construction, 
it  may  have  some  plus  value  with  relation  to  the  ground-water 
table  in  order  that  the  work  of  excavation  may  be  "in  the  dry." 
The  head  BD  between  the  ground-water  table  and  the  vacuum 
line  is  made  up  of  two  parts,  the  part  BC  representing  the  dis- 
tance between  the  normal  water-table  and  the  depressed  water- 
table  at  the  wells,  or  the  head  consumed  in  producing  the  flow  of 


GROUND-WATER  SUPPLY.  77 

water  through  the  sand  towards  the  system  of  wells,  or  the  value 
i  in  the  general  formula  v=ki;  the  other  part  CD  is  the  head  con- 
sumed in  overcoming  the  resistance  of  the  strainer  and  the  entire 
pipe  system.  Now  since  the  head  BC  is  the  effective  head  which 
delivers  the  water  to  the  wells  through  a  highly  resisting  material, 
the  sand,  it  follows  that  it  should  be  impaired  in  the  operation  as 
little  as  possible  by  frictional  resistance  through  the  wells  and 
pipes  of  the  water-supply  system,  or,  to  state  the  case  diagram- 
matically,  the  flow  head  BC  should  be  large  with  respect  to  the 
pipe  friction  head  DC. 

Certain  conditions  of  flow  may  be  assumed  in  order  to  illustrate 
in  the  diagram  the  relation  of  flow  head  to  friction  head.  Let  a 
siphon  pipe  be  1000  feet  long,  12  inches  in  diameter  from  the  most 
remote  well  to  the  suction  well,  connected  at  each  100  feet  of  its 
length  with  a  tubular  well,  each  well  furnishing  100,000  gallons  of 
water  a  day.  It  may  also  be  assumed  that  the  yielding  capacity  of 
the  sand  has  been  the  basis  of  the  above  estimate  of  yield  per 
well  and  that  the  well  and  its  strainer  and  drop-pipe  have  been 
proportioned  for  a  frictional  resistance  of  3  feet. 

The  frictional  resistance  in  the  siphon  changes  with  the  ad- 
dition of  a  well  at  every  100  feet  of  its  length  and  is  cumulative, 
that  is  to  say,  that  the  resistance  in  section  10,  including  the 
drop-pipe,  is  due  to  the  flow  of  water  from  all  the  wells;  the  re- 
sistance head  at  well  9  is  the  resistance  at  well  10  plus  the  re- 
sistance of  a  flow  of  900,000  gallons  per  24  hours  through  100  feet 
of  pipe  between  wells  9  and  10,  the  resistance  at  wells  8  is  that  at  9 
plus  the  resistance  of  a  flow  of  approximately  800,000  gallons 
through  its  section  of  100  feet  of  pipe,  etc.  We  compute  the  resist- 
ance head  at  well  10,  including  strainer  and  drop-pipe,  at  3.2 
feet  and  that  at  well  i  at  3.6  feet,  and  a  velocity  varying  from  2 
feet  at  well  10  to  about  0.2  of  a  foot  per  second  at  well  i. 

Now  suppose  it  were  desired  to  double  the  supply  of  water 
by  extending  the  12-inch  pipe  1000  feet  and  by  adding  10  ad- 
ditional wells,  making  the  total  length  of  the  water-supply  line 
2000  feet  with  20  wells  attached.  We  would  then  have  an  as- 
sumed discharge  of  2,000,000  gallons  at  original  well  10,  and 
1,000,000  gallons  at  original  well  i,  and  a  corresponding  resistance 
line  GF  much  steeper  than  the  former  line  EF  and  showing  a 


78  WATER-SUPPLIES. 

resistance  head  at  well  10  of  3.7  feet,  while  at  well  i  it  is  7.5, 
with  a  velocity  of  flow  varying  from  2  feet  at  well  i  to  nearly  4 
feet  at  well  10. 

The  heavy  resistance  head  at  well  i  resulting  from  an  effort 
to  put  an  additional  1,000,000  gallons  of  water  through  the 
original  1000  feet  of  siphon  pipe  extends  its  effect  throughout 
the  extension  and  leaves  a  very  much  reduced  head,  HG,  to  in- 
fluence the  velocity  of  approach  of  the  ground- water  to  the  wells. 

The  hydraulic  conditions  will  not  manifest  themselves  pre- 
cisely as  outlined,  because  in  the  actual  adjustment  of  the  hydrau- 
lic conditions  the  true  hydraulic  slope  line  will  lie  somewhere 
between  the  line  EF  and  GF  corresponding  to  some  intermediate 
rate  of  discharge  from  the  20  wells  on  the  2000  feet  of  siphon 
pipe  considerably  below  the  2,000,000  gallons  rate  used  as  the 
basis  of  this  estimate,  the  case  being  somewhat  exaggerated  to 
show  the  error  into  which  one  may  fall  if  due  consideration  is 
not  given  the  question  of  probable  future  requirements  in  the 
original  design  and  construction.  Had  the  future  requirements 
been  anticipated  in  the  first  illustration,  the  size  of  siphon  pipe 
would  have  been  fixed  larger  than  12  inches. 

An  effort  to  increase  the  flow  of  the  entire  system  of  wells,  by 
independently  increasing  the  vacuum  on  the  siphon,  would  create 
conflicting  siphonic  conditions  whenever  that  vacuum  line  falls 
below  the  vacuum  line  indicated  by  the  level  of  the  water  in  the 
well,  for  then  the  direction  of  siphon-action  would  be  reversed 
from  the  point  where  the  independently-made  vacuum  line  falls 
below  the  water-level  of  the  suction- well,  and  accordingly  there 
would  be  a  tendency  towards  flow  from  the  suction-well  into  the 
ground.  Moreover,  this  siphon  pipe  should  be  large  enough  that 
a  line  KL  drawn  parallel  with  the  ground-water  hydraulic  grade 
line  of  the  highest  possible  rate  of  draft,  from  a  point  K,  25  feet 
above  the  vacuum  line,  shall  be  above  the  siphon  at  all  points, 
otherwise  the  siphon  will  flow  only  partially  full  or  with  a  pulsat- 
ing flow  through  that  portion  above  the  line  KL. 

There  is  no  necessity  of  setting  the  pumps  or  the  siphon  pipe 
lower  than  is  necessary  to  produce  a  vacuum  which  insures  an 
average  depression  of  the  ground- water  table  lower  than  one-half 
the  depth  of  water-bearing  stratum. 


GROUND-WATER  SUPPLY.  79 

In  order  to  guard  against  all  conflicting  conditions  it  is 
necessary  to  thoroughly  study  the  local  conditions  and  to  start 
the  original  construction  with  due  regard  to  probable  future  re- 
quirements and  a  harmonious  arrangement  of  the  various  parts 
of  the  water-supply  system.  One  cannot  venture  to  place  precise 
limits  upon  the  velocity  of  flow  and  the  loss  of  head  due  to  pipe 
resistance  in  a  siphon  pipe  without  definite  information  regarding 
local  conditions  and  requirements.  However,  an  endeavor  has 
been  made  to  make  clear  the  general  requirement  that  both  of 
these  elements  should  be  given  a  consistent  minimum  in  any 
well-water-supply  design  where  the  depth  of  water-bearing  mate- 
rial is  small  and  accordingly  where  every  foot  of  head  of  ground- 
water  down  to  the  level  producing  the  condition  of  maximum 
flow  should  be  utilized  advantageously.  For  let  it  be  remembered 
that  every  foot  of  head  used  to  overcome  resistance  of  flow  in 
pipes  is  just  so  much  head  diverted  from  velocity  effect  upon 
the  ground-water  approaching  the  wells  through  the  surround- 
ing sand-bed.  Moreover  it  is  always  desirable  to  make  the 
draft  from  each  well  of  the  system  of  wells  as  nearly  uniform 
and  equal  as  practicable,  which  is  an  impossible  result  with  a 
gang  of  wells  operated  under  high  suction  or  siphon  pipe-resist- 
ance; for  in  this  case  the  rapidly  ascending  hydraulic  gradient 
of  the  ground-water  parallel  with  the  gang  of  wells  results  in 
a  rapid  and  progressive  decrease  of  yield  of  the  individual  wells 
in  a  direction  away  from  the  suction-well  or  the  pumps,  and 
finally  reaches  a  point  where  the  hydraulic  grade  line  approach- 
ing nearly  to  the  normal  level  of  the  water-table  admits  of  no 
flow  or  only  a  pulsating  flow  of  remote  wells. 

Returning  to  a  consideration  of  a  tubular-well  and  siphon 
system  suited  to  the  condition  of  water-bearing  stratum  illus- 
trated by  Fig.  2,  on  page  51,  where 

h=2O  feet,  the  depth  of  water-bearing  material, 
&=iooo  for  a  No.  36  sand, 
/=5oo  feet, 

the  maximum  discharge  of  the  direct  current  of  approach  of 
water  through  the  sand  is  to  be  found  by  substitution  in  the 
formula 


8o  WATER-SUPPLIES. 

Q  =  --  —=200  cu.  ft.  per  day  per  lin.  ft.  and  double  this 
amount,  or  400  cu.  ft.  per  day,  for  both  sides  of 
a  line  of  wells. 

The   average  maximum   discharge   of   a  tubular  well  under 
the  conditions  stated  may  be  approximated  by  formula  (15). 


(?max.  =  0.0475  XM2=  19,000  cu.  ft.  per  day. 

The  distribution  of  the  wells  may  be  approximated  by  divid- 
ing 19,000  cu.  ft.,  the  capacity  of  one  well,  by  400  cu.  ft.,  the 
discharge  per  lineal  foot  of  water-bearing  material  under  a  head 

7. 

of  -  =10  feet,  and  amounts  to  47.5  feet. 

Having  no  analysis  of  the  water-bearing  material,  assume  it 
to  be  uniformly  a  No.  36  sand,  the  size  previously  computed. 
Observations  of  the  capacity  of  an  ordinary  slotted  brass  strainer 
with  slots  i^  inches  long  by  1/32  of  an  inch  wide  and  13  per 
cent  of  the  total  metal  surface  indicate  a  capacity  of  about 
12,000  gallons  or  1600  cu.  ft.  per  day  per  lineal  foot  in  fine  sand. 
Accordingly  a  strainer  of  this  rated  capacity  should  be  about 
12  feet  long  to  absorb  19,000  cu.  ft.  of  water  per  day.  But  as 
the  limit  of  length  is  10  feet  the  deficiency  must  be  made  up  by 
increasing  the  slot  area  or  efficiency  above  that  of  the  rated 
strainer. 

The  velocity  of  radial  flow  at  the  exterior  of  the  strainer  is 

1QOOO 

-  -T-,  or  1210  feet  per  day  for  a  strainer  6  inches  in  diameter. 
This  diameter  tested  by  formula   (16)  became 

0.03X1000x20 
d  =  -  -  —    -  •  =0.495  of  a  foot. 

I2IO 

The  diameter  of  a  drop-pipe  which  can  discharge  19,000  cu.  ft. 
or  142,500  gallons  per  day  with  a  frictional  loss  of  i  foot  in 
25  feet,  including  valves  and  fittings,  is  about  3  inches.  The 
requisite  diameter  of  drop-pipe  is  so  much  less  than  the  diameter 
of  the  well  that  the  open-well  plan  of  development  naturally 
suggests  itself.  Of  course  the  drop-pipe  should  be  as  short  as 


GROUND-WATER  SUPPLY.  81 

possible,  but  as  it  must  descend  to  within  a  foot  or  two  of  the 
bottom  of  the  well  the  vertical  portion  must  approximate  15  feet 
and  the  horizontal  portion  between  the  well  and  siphon  should 
be  10  feet  or  a  little  less. 

Practically  the  wells  should  be  distributed  alternately  on 
either  side  of  but  near  the  siphon  pipe,  about  48  feet  apart. 
Mutual  interference  among  the  wells  so  arranged  must  necessarily 
result,  but  as  they  are  designed  of  a  capacity  to  absorb  the  direct 
maximum  flow  of  water  from  both  sides  of  the  alignment,  the 
question  of  mutual  interference  becomes  a  matter  of  little  or 
no  importance. 

If  the  average  draft  from  the  wells  is  3,500,000  gallons  per 
day  and  the  rate  of  emergency  draft  is  5,000,000  gallons  per  day, 
then  under  the  conditions  of  the  problem  the  number  of  wells 
becomes  5,000,000^-142,500=35,  and  the  total  length  of  the  line 
of  development  1680  feet. 

The  siphon  pipe  should  be  large  enough  for  the  stated  maxi- 
mum flow  plus  a  reasonable  allowance  of  capacity  to  admit  of 
future  extension,  but  as  there  is  no  adequate  data  limiting  the 
supplying  capacity  of  this  particular  valley  it  may  be  assumed 
for  the  purpose  of  this  illustration  that  through  an  extension 
of  the  wells  the  supply  may  be  increased  about  50  per  cent,  or 
to  about  7,500,000  gallons.  Accordingly  the  siphon  capacity 
should  be  designed  for  a  total  length  of  about  2500  feet  with 
a  capacity  of  7,500,000  gallons  at  or  near  the  suction-well  and 
proportionately  less  capacity  as  the  pipe  recedes  for  that  well. 
Inasmuch  as  it  is  desired  to  make  the  greatest  use  of  the  ground 
storage  and  to  insure  as  high  a  yield  as  possible  of  each  well, 
a  low  friction  head  should  be  maintained  throughout;  in  fact,  for 
so  thin  a  water-bearing  material,  the  siphon-pipe  resistance  should 
scarcely  exceed  a  rate  of  2  feet  per  thousand  for  the  average  draft, 
or  4  feet  per  thousand  for  maximum  draft.  Accordingly  the 
diameters  and  lengths  of  the  siphon  pipe  for  an  average  draft 
of  5,000,000  gallons  per  day  at  the  suction-well  may  be  1000'  of 
24",  500'  of  20",  500'  of  16",  250'  of  12",  and  250'  of  10"  pipe, 
offering  a  total  resistance  of  about  1.6  feet  for  the  average  rate 
of  draft  and  3.6  feet  for  the  maximum  rate  of  draft. 

The  stated  continuous  yield  of  5,000,000  gallons  of  water 


8  2  WA  TER-SUPPLIES 

from  2500  feet  of  tubular-well  development  depends  upon  the 
extent  to  which  it  can  be  sustained  by  the  rainfall  together  with 
the  substantial  assistance  of  river  reinforcement  when  necessary, 
and  embraces  a  discharge  of  2000  gallons  from  two  sides  or  1000  gal- 
lons from  one  side  per  lineal  foot  of  the  line  of  development. 
It  requires  an  average  velocity  of  approach  of  over  6  feet  per 
day  in  terms  of  a  solid  column  of  water  at  a  grade  of  about  24  feet 
per  1000  feet  and  a  catchment  area  extending  over  6J  miles  back 
from  the  line  of  development  absorbing  17  inches  of  the  annual 
rainfall,  or  heavy  local  river-reinforcement. 

Where  conditions  confine  the  support  of  the  yield  largely  to 
one  side  of  the  line  of  development,  the  foregoing  measure  of 
velocity,  grade,  and  area  of  catchment  territory  must  be  propor- 
tionately greater  or  the  yield  must  be  better  sustained  by  river 
reinforcement. 

For  a  second  illustration  consider  the  Muscatine  conditions, 
where  the  saturated  bed  of  gravel  is  35  feet  deep  of  an 
average  effective  size  of  sand  of  No.  18,  corresponding  to  a  value 
of  k  equal  to  4000,  but  underlaid  with  10  feet  of  No.  13.5  gravel, 
corresponding  to  a  value  of  k  equal  to  8337.  The  greatest  per- 
missible depression  of  the  ground-water  table  by  pumping  is  10 
feet  and  the  corresponding  value  of  discharge  for  average  porosity 
of  the  sand  by  formula  13  becomes 

Q=o.igkx(h-x)  =0.19,  4000,  25 (35 -25)  =190,000  cu.  ft. 
per  day,  equivalent  to  a  velocity  of  radial  flow  at  the  circumference 

TQOOOO 

of  a  6-inch  well  of  — =4840  feet  per  day.  But  as  it  is  de- 
sired to  confine  the  strainer  to  the  10  feet  of  coarse  material  and 
at  the  same  time  take  advantage  of  the  full  yield  of  water  for  the 
10  feet  of  available  head,  the  requisite  velocity  of  radial  flow 

becomes         -X  4840  =10,088    feet    per    day.     Accordingl     the 
4000 

strainer  must  have  a  diameter  which  admits  of  the  cutting  of  a 
grade  of  slots  which  shall  have  sufficient  hydraulic  efficiency  to 
absorb  water  at  the  rate  of  190,000  cu.  ft.  per  day. 

Applying    formula    (17)   we   find    for    the   grade   of    sand 


GROUND-WATER  SUPPLY.  83 

represented   by  value    £=^8337    the    requisite   area  of  strainer 
openings  to  be 

bd  =0.00065,  8337,  25^/35-25=428  sq.  in. 

Thus  in  very  coarse  material  like  that  at  Muscatine  a  single 
well  with  a  properly  proportioned  strainer  can  be  expected  to 
furnish  an  exceedingly  large  volume  of  water. 

The  layout  of  a  well  system  may  be  proportioned  as  to  the 
length  of  development  by  the  diagram  shown  on  page  47,  while 
the  strainer  capacity  and  pipe  resistance  should  be  proportioned 
for  the  emergency  yield  when  a  draft  upon  storage  is  generally 
necessary. 

Probably  no  difficulty  will  be  experienced  in  comparing  the 
costs  of  the  gallery  and  the  tubular-well  methods  of  water-supply 
development  upon  the  basis  outlined,  and  it  is  hoped  that 
the  approximate  formulae  may  prove  of  assistance  not  only  in 
making  this  comparison,  but  also  in  the  design  of  ground-water 
supplies  where  large  yields  are  required. 


The  proximity  of  a  town  to  a  desirable  locality  for  the  de- 
velopment of  a  ground-water  supply  may  sometimes  be  a  source 
of  apprehension  and  is  often  considered  a  condition  calling 
for  a  thorough  sanitary  investigation  of  the  underflow.  If 
the  desirable  locality  is  above  the  town,  that  is  to  say  up-stream 
with  regard  to  the  direction  of  the  slope  of  the  underflow,  an 
investigation  is  unnecessary  for  the  reason  that  the  pollution 
which  might  enter  the  underflow  from  the  town  would  natu- 
rally follow  the  drift  of  the  underground  water.  Undoubtedly 
a  location  above  the  town  of  a  ground-water  supply  is  a  safe 
precaution,  but  the  danger  of  pollution  of  a  similar  water- 
supply  located  below  the  town  may  be  often  overestimated 
and  exaggerated.  For  instance,  the  valleys  of  such  rivers  as  the 
Mississippi  and  Missouri  possess  a  slope  in  the  direction  of  flow  of 
the  rivers  practically  the  same  as  the  rivers  themselves  and  scarcely 
exceeding  in  the  two  valleys  referred  to  and  similar  ones  6  to  12 
inches  per  mile,  or  from  0.095  to  0.19  of  a  foot  per  thousand  feet. 


#4  WATER-SUPPLIES. 

This  exceedingly  small  slope  can  scarcely  produce  a  velocity  of 
ground- water  flow  in  the  direction  of  the  valley  greater  than  four- 
or  five-tenths  of  a  foot  per  day,  and  is  rendered  almost  ineffec- 
tive by  reason  of  the  controlling  effect  of  the  slope  approximately 
normal  to  the  general  direction  of  the  river,  which  usually  exceeds 
the  former  tenfold  or  more.  The  influence  of  flow  riverward  so 
far  predominates  that  the  underdrainage  from  the  town  can  pro- 
gress but  slightly  in  a  direction  parallel  with  the  river.  The  drive 
of  ground-water  inland  during  a  rise  of  the  river  can  scarcely 
modify  the  general  direction  of  flow  riverward,  because  when  the 
crest  of  the  flood-wave  has  passed  and  the  river  recedes  rapidly 
the  resulting  increased  ground-water  slope  accelerates  the  under- 
flow in  the  direction  of  the  river. 

A  local  drought  may  flatten  the  ground-water  table  somewhat, 
but  scarcely  to  the  extent  of  giving  the  balance  of  power  to  a 
parallel  tendency  of  flow.  Should  the  drought  become  protracted 
and  extensive  its  influence  progressively  reduces  the  discharge 
of  the  river  and  the  resulting  falling  stage  maintains  the  normal 
slope  of  the  water-table  as  the  river  draws  upon  the  underground 
storage  for  its  support. 

It  is  conceivable,  however,  that  in  valleys  of  heavy  slope  the 
parallel  flow  may  at  times  predominate.  In  that  event  the  ele- 
ment of  time  becomes  a  factor  and  the  interval  which  must  elapse 
between  the  introduction  of  pollution  from  town  drainage  and  the 
arrival  of  the  water  at  the  site  of  the  water-supply  may  be  fully 
sufficient  to  remove  everything  but  the  evidence  of  past  pollution. 
A  study  of  local  conditions  should  in  any  case  determine  whether 
apprehensions  of  pollution  have  any  substantial  support. 

Generally  the  danger  of  serious  pollution  of  the  character 
referred  to  is  to  be  guarded  against  chiefly  in  the  immediate 
neighborhood  of  the  water-supply  works,  and  if  proper  precautions 
are  here  observed  to  prevent  deposits  of  polluting  matter  under- 
ground the  really  dangerous  element  of  underground-water  pol- 
lution will  have  largely  disappeared. 


GROUND-WATER  SUPPLY.  85 


Removal  of  Iron. 

Iron  in  considerable  amount  in  a  ground-water  imparts  to 
it  an  inky  taste,  a  disagreeable  odor  when  accompanied,  as  it  often 
is,  by  sulphuretted  or  carborated  hydrogen  gas,  and  upon  stand- 
ing a  repulsive  yellowish  appearance.  A  water  containing  iron  is 
colorless  and  transparent  when  freshly  drawn  from  the  ground,  and 
to  all  appearances  as  inviting  as  any  spring-water.  The  slightly 
disagreeable  taste  ceases  to  repel  upon  acquaintance,  particularly 
under  the  impression  that  this  class  of  water  possesses  medicinal 
properties.  It  is  only  upon  standing  that  its  attractiveness  as  a 
beverage,  either  for  medicinal  or  natural  purposes,  ceases,  for  the 
partially  oxidized  iron  held  in  solution  by  carbonic  acid  quickly 
absorbs  oxygen  from  the  atmosphere,  becomes  disunited  from 
the  carbonic  acid,  and  assumes  the  state  of  an  insoluble  mineral 
sediment  of  a  yellowish  color.  The  discolored  water  clears  as  the 
iron  sediment  gradually  settles,  but  not  without  a  tell-tale  oily 
appearing  film  upon  the  surface  of  the  clarified  water.  Con- 
tinued exposure  darkens  the  sediment  to  a  deep  rusty  shade  which 
adheres  very  firmly  to  any  vessel  repeatedly  exposed  to  the  water. 

This  peculiarity  of  the  iron  to  discolor  utensils  of  various 
kinds  renders  it  particularly  objectionable  for  domestic  uses,  and 
to  even  a  greater  degree  in  cooking  because  of  the  offensively 
rusty  color  it  imparts  to  many  vegetables  and  the  deep  inky 
shade  it  dyes  tea  and  coffee. 

While  the  presence  of  iron  in  a  ground- water  in  sufficient  amount 
to  precipitate  upon  exposure  to  air  is  readily  detected  visually 
by  one  acquainted  with  its  character,  still  there  are  instances 
where  its  presence  and  general  characteristics  became  a  com- 
plete revelation  to  communities  which  have  preferred  ground- 
water  to  other  sources  of  public  water-supply.  They  either 
never  suspected  its  presence  in  the  selection  of  the  source  of  supply 
or  were  wholly  uninformed  as  to  the  many  annoyances  which 
always  follow  its  use  for  general  water-supply  purposes.  Asso- 
ciation with  it  as  a  public  water-supply  never  reconciles  one  to 
its  use.  It  is  regarded  in  sort  of  a  spirit  of  toleration  as  a  thing  to 
be  endured  for  a  time,  mingled  with  the  ever-present  hope  that  a 


86  WATER-SUPPLIES. 

remedy  can  be  none  too  speedy.  The  rusty-colored  liquid  which 
marks  the  morning  flushing  of  a  service  pipe  or  is  periodically 
ejected  from  a  hydrant  on  the  dead  end  of  a  street  pipe  does  not 
inspire  one  with  much  faith  in  the  medicinal  qualities  of  a  chaly- 
beate water  whatever  the  facts  may  be  with  reference  to  the 
water  freshly  drawn  from  the  ground;  in  fact  there  is  no  asso- 
ciation with  it  about  the  household  that  can  inspire  much  respect 
or  promote  much  friendship  for  it. 

The  remedy  for  iron  in  water  has  many  suggestions  in  nature. 
Wherever  spring-water  containing  iron  emerges  from  the  ground 
a  rusty  deposit  follows  the  course  of  the  rivulet  for  a  considera- 
ble distance  from  its  source.  The  oxide  of  iron,  adhering  firmly 
to  almost  any  obstruction  with  which  the  mineralized  water  comes 
in  contact,  is  the  result  of  the  aeration  which  the  water  naturally 
receives  during  the  first  brief  period  of  its  surface  flow.  This 
natural  process  of  oxidation  by  aeration  can  be  much  hastened 
by  spraying  the  water  in  any  manner  which  will  expose  it  thor- 
oughly to  the  atmosphere.  It  has  been  successfully  practiced 
abroad  for  many  years  and  to  a  more  limited  extent  and  for  a 
briefer  period  of  time  in  this  country. 

The  attractive  part  of  the  process,  although  purely  a  chemical 
process,  is  that  it  is  altogether  natural  and  accordingly  requires 
the  use  of  no  chemical  to  promote  chemical  action.  The  air 
supplies  the  chemical  that  is  needed  to  oxidize  the  iron  and 
reduce  it  to  an  insoluble  condition.  Another  attractive  feature 
is  that  the  process  may  be  applied  very  cheaply  and  equally 
successful  on  a  large  scale  as  well  as  on  a  small  scale. 

After  the  iron  is  precipitated  as  an  insoluble  oxide  the  problem 
of  straining  or  filtering  out  of  the  water  the  iron  sediment  is  a 
problem  in  many  respects  similar  to  the  clarification  of  a  slightly 
muddy  surface-water.  As  much  as  90  per  cent  of  the  iron  may 
be  removed  by  sedimentation  practiced  under  very  favorable 
conditions,  perhaps  more  favorable  than  is  attainable  in  operat- 
ing a  water-works.  The  process  of  sedimentation,  however,  is 
too  uncertain  to  apply  to  the  removal  of  iron  except  as  a  pre- 
liminary process  intended  to  precede  and  to  lessen  the  work  of 
filtration. 

It  is  not  unusual  to  find  iron  present  in  ground-water  to  the 


GROUND  WATER  SUPPLY.  87 

extent  of  one-half  to  one  grain  per  gallon,  but  in  one  instance 
the  amount  was  observed  to  reach  the  high  figure  of  over  four 
grains  to  the  gallon,  an  abnormal  condition,  however,  produced 
possibly  by  the  existence  for  many  years  of  stock-yards  upon 
the  ground  under  which  the  sample  tested  was  extracted. 

The  iron  in  aerated  ground-water  may  be  removed  by  nat- 
ural filtration  through  comparatively  coarse  sand  at  a  rate  much 
in  excess  of  that  ordinarily  employed  in  slow  sand  filters  for  the 
purification  of  water  polluted  with  sewage. 

The  depth  to  which  the  iron  penetrates  the  filter  sand  depends 
altogether  upon  the  rate  of  filtration.  At  a  rate  of  300  to  400  gal- 
lons per  square  foot  per  day  it  is  found  that  the  removal  of  a 
layer  of  about  three-quarters  of  an  inch  of  sand  at  a  cleaning  will 
restore  the  effectiveness  of  the  filter  at  least  to  an  extent  that 
with  progressive  scrapings  of  the  stated  amount  the  filter  renders 
effective  service  until  the  sand-bed  reaches  the  practical  minimum 
of  thickness  before  the  sand  removed  at  the  various  scrapings 
is  returned  to  its  original  place  in  the  filter.  The  three-quarters 
of  an  inch  does  not  represent  the  extent  of  the  penetration  of 
iron  into  the  filter  sand,  as  it  is  found  at  a  depth  of  6  inches, 
but  the  clogging  effect  is  confined  to  practically  the  upper  three- 
quarters  of  an  inch  and  chiefly  in  the  film  of  iron  which  covers 
the  surface  of  the  filter  sand. 

The  ordinary  rate  of  filtration  employed  in  mechanical  filters 
is  fully  seven  times  the  rate  above  mentioned,  or  about  2000  to 
2800  gallons  per  square  foot  per  day,  and  would  carry  the  iron 
deep  into  the  sand,  and  at  times  carry  it  entirely  through  the 
filter  into  the  filtrate  unless  a  coagulant  be  used.  Although  iron 
itself  is  a  coagulant  when  employed  to  remove  ordinary  sedi- 
ment from  water,  still  when  iron  itself  becomes  the  sediment  it  is 
sought  to  remove,  the  process  is  then  akin  to  the  removal  of 
hydrate  of  alumina  from  a  water  treated  with  a  solution  of  alum. 

A  little  over  a  year  ago  a  water-purification  works  was  installed 
at  Richmond,  Missouri,  which  so  successfully  removed  the  iron 
from  the  water  that  a  description  may  prove  interesting. 

The  source  of  supply  is  from  four  8-inch  wells,  about  25  feet 
apart,  of  an  aggregate  capacity  of  800,000  gallons  of  water  per 
twenty-four  hours.  The  well-strainers  are  16  feet  long,  resting 


WATER  SUP  PLIES. 

upon  the  bed-rock  underlying  the  Missouri  River  valley  and 
surrounded  by  a  stratum  of  coarse  sand  21  feet  thick  overlaying 
the  rock.  The  site  of  the  water-supply  is  about  four  miles  from 
the  town  and  is  the  only  accessible  site  promising  to  furnish  an 
unfailing  supply  of  water. 

Although  the  presence  of  iron  in  the  ground-water  was  observed 
at  the  time  the  works  were  constructed  over  seven  years  ago, 
no  funds  were  then  available  for  a  purification  works  and  accord- 
ingly no  effort  was  made  at  the  time  to  introduce  them.  It 
was  remarked  at  the  time  of  construction  that  the  iron  might 
diminish  with  the  protracted  and  continuous  use  of  the  water, 
but  after  six  years  of  water  service  the  iron  increased  rather 
than  diminished,  and  at  the  time  of  the  construction  of  the  puri- 
fication works  the  iron  amounted  to  about  f  of  a  grain  to  the 
gallon  or  about  12  parts  per  million.  During  the  six  years  of  use 
of  the  iron  water  the  annoyance  gradually  increased  and  popular 
objection  intensified  accordingly. 

The  results  of  the  operation  of  an  experimental  plant  erected 
and  operated  for  the  purpose  of  demonstrating  the  feasibility  of 
removing  the  iron  led  to  the  following  conclusions: 

1.  Aeration  completely  precipitates  the  iron  and  reduces  it 
to  a  condition  in  which  it  can  be  partially  removed  by  subsi- 
dence and  thoroughly  removed  by  filtration. 

2.  Subsidence  alone  can  remove  but  about  80  per  cent  of 
the  iron  under  favorable  conditions  in  a  subsiding  basin  of  a 
capacity  one  and  one-half  or  more  times  greater  than  the  maxi- 
mum daily  water  consumption. 

3.  Filtration  of  the  aerated  water  removes  practically  all  the 
iron,  that  is  to  say,  reduces  it  to  0.05  part  per  million. 

4.  The  amount  of  iron  in  the  natural  water  is  so  large  that 
preliminary  subsidence  after  aeration  of  the  water  will  reduce 
the  work  of  the  filter  and  prolong  its  life  between  scrapings. 

5.  By   combining   in   one   process   aeration,   subsidence,   and 
nitration  an  attractive  water  can  be  furnished   which  will    be 
found  as  pure  and  wholesome  as  the  best  spring-water. 

The  purification  plant  as  constructed  consists  of  three  con- 
centric rings  of  concrete.  The  inner  ring  is  17  feet,  the  mid- 
dle ring  38  feet,  and  the  outer  ring  60  feet  in  diameter,  as 


GROUKD-WATER  SUPPLY.  8^ 

shown  by  the  sectional  elevation,  Fig.  14.  The  rings  are  re- 
spectively 6  inches,  n  inches,  and  18  inches  thick.  The 
annular  space  between  the  concentric  rings  is  10  feet,  the 
depth  6J  feet  in  the  subsiding  and  aerating  basins,  nj  feet  in 
the  filter,  and  13  feet  in  the  clear-water  basin.  The  space  inside 
the  inner  curb  is  the  aerating  basin  connecting,  by  means  of  two 
notches  18  inches  wide  and  12  inches  deep,  with  the  annular 
space  between  the  inner  and  middle  curbs  which  forms  the  sub- 
siding basin.  The  annular  space  between  the  middle  and  outer 
rings  is  divided  by  transverse  walls  into  three  divisions;  one- 
half  the  annular  space  is  the  clear-water  basin  and  the  other 
half,  divided  equally  by  a  third  division  wall,  forms  the  two 
filter  receptacles.  There  is  a  regulating  well  at  each  of  the 


FIG.  14. 

two  division  walls  separating  the  filters  from  the  clear-water 
basins,  which  receives  the  water  from  the  filter  underdrains  and 
delivers  it  into  the  clear-water  basin  through  valves  set  at  differ- 
ent elevations  and  attached  to  pipes  passing  through  the  division 
walls.  By  means  of  these  valves  the  rate  of  flow  from  the  filter 
can  be  controlled  within  desirable  limits. 

The  clean-out  opening  for  each  filter  consists  of  a  1 4-inch 
sluice  gate  set  in  the  outside  curb  and  housed  with  concrete  side 
walls  and  cover  extending  to  the  slope  of  the  earth  embankment. 

The  subsiding  basin  connects  with  the  filter  by  a  6-inch  pipe 
with  attached  stop-valve,  which  is  carried  upward  inside  the 
subsiding  basin  to  a  level  a  few  inches  below  the  roof.  An 
overflow  pipe  connecting  with  the  subsiding  basin  limits  the 
level  of  the  water. 

The  drain-pipe  connecting  with  both  the  subsiding  basin  and 
the  aerating  basin  has  a  stop-valve  outside  the  embankment 
and  a  disc  valve  inside  the  aerating  basin. 


90  WATER-SUPPLIES. 

A  6-inch  pipe  delivers  the  water  from  the  well  pump  into 
the  aerator.  The  aerator  consists  ot  four  trays,  each  2  feet  by 
6  feet  in  the  clear  and  6  inches  deep  attached  at  two  feet  inter- 
vals to  four  posts  set  upright  on  the  bottom  of  the  aerator  basin. 
Each  of  the  four  pans  has  a  bottom  of  No.  8  wire  net  with  f-inch 
mesh  supporting  a  galvanized  iron  lining  pef orated  with  ^-inch 
holes  spaced  \  inch  apart.  The  water  from  the  rising  main 
enters  the  uppermost  tray  in  a  sheet  about  6  feet  wide  and 
showers  down  through  the  perforations  of  the  succeeding  pans 
into  the  basin  below.  The  total  drop  of  the  water  is  about  8  feet. 

An  8-inch  suction-pipe  connects  the  clear-water  basin  with 
the  high-pressure  pump  which  delivers  the  purified  water  to 
the  consumers. 

The  bottom  of  the  clear-water  basin  and  filter  receptacles, 
the  center  and  the  inner  curbs  and  the  roof  are  all  of  1-3-5  lola 
Portland-cement  concrete,  reinforced  with  the  Johnson  cor- 
rugated steel  rods.  The  exterior  curbing  is  banked  with  earth 
and  the  concrete  roof  has  a  covering  of  earth  18  to  24  inches 
deep. 

The  aerator  is  surrounded  by  a  concrete  curb  2  feet  high 
and  a  brick  curb  for  an  additional  height  of  7  feet.  It  is  open 
at  the  top. 

The  bottom  of  the  filter  receptacles,  clear-water  basin,  and 
aerator  basin  were  constructed  in  radial  block  alternately.  The 
outside  curb  of  the  clear-water  basin  and  one-half  of  two  division 
walls  were  constructed  monolithic.  The  middle  curb,  the  other 
half  of  the  two  division  walls  above  referred  to,  the  regulating 
wells,  the  outside  curb  of  the  filters,  and  half  the  division  wall 
between  the  two  filters  are  constructed  monolithic  as  shown  by 
Plate  VII,  page  91.  Plate  VIII,  page  93,  shows  the  inner  curb 
completed  and  the  outer  forms  removed;  Plate  VII  is  also  a  gen- 
eral view  of  the  work  during  construction.  Plate  IX,  on  page  95, 
and  Plate  X,  on  page  97,  show  details  of  construction  at  different 
stages  of  progress.  Plate  IX  in  particular  gives  an  interesting  view 
of  the  method  of  constructing  the  roof  slabs  of  concrete  in  forms 
suspended  from  A-shaped  wood  frames.  The  entrance  to  the 
clear-water  basin  is  where  the  ladder  is  seen  protruding,  the  square 
opening  is  the  regulating  well,  the  A  frames  over  the  filters  with 


•r    L 


OF  THE 

I    UNIVERSITY 


c 


B? 


"V 


OF  THE 

UNIVERS 

Of 

LlFOKi 


GROUND-WATER  SUPPLY.  99 

attached  platform  are  in  readiness  to  receive  the  concrete  and 
steel  for  a  reinforced  radial  roof  block.  The  roof  blocks  were 
put  in  alternately.  The  platform  which  had  served  the  pur- 
pose of  support  for  the  construction  of  one  radial  roof  block  was 
loosened  at  the  end  of  about  a  week  and  pushed  laterally  on  the 
girders  suspended  by  bolts  to  a  pair  of  rafters,  to  the  opening  of  an 
alternate  block  and  thus  acted  as  a  support  for  a  second  block 
of  concrete.  The  6-inch  radial  channels  left  after  the  removal 
of  the  A  trusses  were  then  filled  in  on  a  plank  suspended  be- 
neath the  opening. 

Plate  XI,  page  101,  shows  the  completed  structure  with  its 
earth  covering. 

Plate  XII,  on  page  103,  is  the  aerator  in  operation. 

The  concrete  was  of  mobile  consistency  when  put  in  the 
forms  and  required  no  ramming.  A  hoe  with  a  straightened 
shank  was  used  to  work  the  mortar  about  the  steel  and  to  a 
smooth  face  at  surface  of  contact  with  the  forms.  There  was 
no  occasion  to  retouch  with  a  trowel  the  concrete  faces  except 
when  i,  3,  6  concrete  was  used  in  a  portion  of  the  outer  curb. 
The  forms  were  removed  after  an  interval  of  thirty-six  to  forty- 
eight  hours  after  the  concrete  was  put  in  place,  with  the  exception 
of  the  roof  concrete,  which  was  allowed  one  week's  time  of  set- 
ting before  removing  the  forms. 

The  earth  roof  cover  was  put  on  with  teams  and  scrapers, 
the  teams  passing  indiscriminately  over  the  naked  concrete 
slabs  one  month  after  construction. 

The  filter  underdrain  is  of  lo-inch  split  sewer-pipe  laid  with 
open  joints  upon  the  concrete  bottom  along  the  center  line  of 
each  filter  and  communicating  with  the  regulating  well.  The 
split  pipe  was  covered  with  2j-inch  road  metal,  and  over  this 
16  inches  of  screened  stone  of  a  size  to  pass  a  screen  with  i-inch 
mesh  and  rejected  by  a  screen  of  ^-inch  mesh,  including  a  top 
dressing  of  fine  stone  passing  a  J-inch  mesh  and  rejected  by  a 
J-inch  mesh.  The  filter  sand  was  procured  from  a  near-by  bank, 
sorted,  washed,  and  then  deposited  to  a  depth  of  3J  to  4  feet  in 
a  manner  which  avoided  any  tendency  of  stratification.  The 
mechanical  analysis  of  the  sand  is  as  follows. 


loo  WATER-SUPPLIES. 

Passing  No.    6  sieve,  100        per  cent. 
"    10     "        97.8      "       " 
"    14     "        93.46    "       " 
"        "    18     "        87.86    " 

tl     20       "  75.75      "          " 

"   40     V        14.26    "      " 

"  60    "       2.16  cc     tc 

"    80     "          0.68    "       " 

The  effective  size  is  No.  47  or  0.41  mm.;  the  uniformity 
coefficient  2.12. 

The  first  filter  put  in  commission  furnished  the  following 
record: 

ist  day,  filter-head,  6    inches,  rate  367  gallons  per  sq.  ft. 

2d  "  "  8        "         "    367       " 

3d       "  "  9J      "         "    367 

4th  <s  c<         iij-      "         "    367       < 


"     "    " 


t  t          C  C         t  I 


5th  17  367 

6th  "  "         19  "  "  367      «'        "     "    " 

7th  <c  4<         25  tc  "  367      <{        "    <:    " 

8th  <c  30  "  <(  367 

I2th  "  *'         56  <;  (<  367 


c  t        it     1 1    1 1 

It  t  I  (C          t  t 


The  filter  was  scraped  on  the  twelfth  day  after  starting. 
A  run  of  forty-nine  days  gave  the  following  result,  which  sub- 
stantially represents  a  fair  rating  of  the  filters. 

Total  amount  of  water  pumped 3,885,700  gallons 

"  dirty  sand  removed 16. 17  cu.  yds. 

Numbers  of  times  the  filters  were  cleaned 6 

Gallons  of  water   pumped  for   each  i  inch  of 

sand  removed 555,100 

Number  of  cubic  yards  of  sand  removed  for 

each  1,000,000  gallons  of  water  filtered  ...  4.1 
Number  of  gallons  of  water  filtered  for  each  cubic 

yard  of  dirty  sand  removed 240,300 

Within  six  months  after  the  filtered  water  was  supplied  to 
the  city,   the  water  consumption   had  practically  doubled. 


OF  THE      ' 

UNIVER?  - 


GROUND-WATER  SUPPLY.  105 

The  dirty  sand  is  removed  from  the  filter  by  manual  labor 
and  is  washed  in  a  trough  and  stored  in  a  bin  until  needed  to 
replenish  the  filters. 

Since  this  work  was  completed  another  purification  works 
for  a  similar  purpose  has  been  constructed  for  the  town  of  Liberty, 
Missouri.  This  purification  works  is  more  compact  than  the 

PLATE  XIII. 


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2T/0*      *^r       |3 

16 

Filter 

>  Center  Line  of  Filter  and  Drain  FT 

—  i           ^           Reservoir     ^>    ,* 
Manhole                        .               o     i- 

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\ 

Htili        iiU§ 

^i  ' 

1 

Filter 

>                                                                   oi^rainjr 

S  l08""1^        lo'i 

3            Center  Line  of  Filter  and  Drain 

i         Re^rvoir'o    l*« 

IS  ,,l»* 

L 

*  —  lo:<)  ^*           10*1      ^   ] 

*2 

«•' 

^            *-^fer- 

•2 

--1 

Plan  of  Purification  Works  at  Liberty,  Mo. 

Richmond  works  for  the  reason  that  it  was  built  at  the  same 
time  as  the  water-supply  and  pumping  station.  It  is  rectangular 
in  form  and  constructed  of  1-3-5  lola-Portland  cement  concrete 
reinforced  with  the  Johnson  corrugated  steel  rods. 

Plate  XIII  shows  the  plan  and  the  elevation  of  the  purifica- 
tion works. 

Plate  XIV  is  a  view  looking  down  upon  the  roof  of  the  filters 
and  enclosing  parapet  walls  within  which  dirty  filter  sand  is 
washed  and  then  stored.  The  tower  enclosing  the  aerator  is 


i  o  6  WA  TER-SUPPLIES 

shown  immediately  behind  the  men  sitting  on  the  parapet  walls 
and  back  of  the  tower  walls  is  the  wall  of  the  pump-room,  rest- 
ing upon  the  reinfofced-concrete  walls  enclosing  the  clear- water 
basin. 

Plate  XV  shows  the  high-pressure  pumping-engine  installation. 
The  engine  sets  upon  the  roof  of  the  clear-water  basin,  which  is 
also  the  floor  of  the  engine-room.  Through  the  open  doorway 
in  the  partition  wall  the  fronts  of  the  boilers  may  be  seen. 

The  bottom  is  a  continuous  slab  of  concrete  for  both  the 
clear-water  basins  and  the  filters,  but  independent  of  each  other. 
The  side  walls  and  roofs  are  monolithic,  but  so  formed  that  the 
concrete  box  composing  the  filters  is  entirely  independent  of 
that  composing  the  clear-water  basin.  The  several  partition  walls 
in  the  clear-water  basin  are  so  formed  as  to  make  two  regulating 
wells,  a  pump-pit  for  the  well  pump,  and  two  compartments  for 
the  storage  of  filtered  water.  A  concrete  roof  covers  the  portion 
where  water  is  stored  and  forms  the  floor  of  the  engine-room,  a 
stairway  leads  down  into  the  pump -pit,  manholes  are  placed 
over  each  division  of  the  clear-water  basin,  and  wooden  covers 
protect  the  regulating  wells.  The  side  walls  of  the  clear- water 
basin  are  the  foundation  walls  of  the  engine-room  part  of  the 
pumping-station.  The  high-pressure  pump  sets  upon  steel  eye- 
beams  molded  into  and  made  a  part  of  the  roof  of  the  clear- 
water  basin. 

The  foundation  walls  of  the  boiler-house  and  boilers  rest 
upon  natural  earth  and  are  not  monolithic  with  the  clear-water 
basin. 

The  filters  are  divided  by  a  longitudinal  wall  through  the 
center,  forming  two  equal  compartments.  A  concrete  roof  covers 
both  filters  with  the  exception  of  about  5  feet  at  the  end  of  the 
filters  next  to  the  building.  A  parapet  wall  3  feet  high  extends 
entirely  around  the  covered  portion  of  the  filters  and  around 
the  opening  in  the  roof.  A  brick  tower  about  5  feet  high  stands 
upon  the  parapet  wall  surrounding  the  large  openings  into  the 
filters.  This  tower  encloses  two  sets  of  aerator  trays,  one  set 
of  four  for  each  filter.  These  trays  differ  from  those  of  the  Rich- 
mond works  only  in  lineal  dimensions,  being  3  by  4  feet.  The 
water  in  showering  through  the  trays  drops  about  10  feet. 


GROUND-WATER  SUPPLY.  in 

The  covered  portion  of  the  filter-roof  enclosed  by  the  para- 
pet walls  is  for  the  storage  and  washing  of  the  dirty  sand  removed 
from  the  filters.  The  dirty  sand  is  skimmed  from  the  filter  by 
hand,  but  elevated  onto  the  roof  by  means  of  a  hydraulic  ejector 

The  underdrain  of  the  niters  is  composed  of  three  parallel 
lines  of  4-inch  vitrified  tile  with  open  joints  and  12  inches  of 
graduated  road  metal  of  practically  the  same  assorted  sizes  as 
those  of  the  Richmond  works. 

The  mechanical  analysis  of  the  sand,  which  is  4  feet  deep,  is 
as  follows: 

Rejected  by  No.    6  sieve,    1.25  per  cent. 
Passed      "     "      6     "      98.75    " 


" 


<{  "  10  "  95.42  "  " 

"  "  14  "  88.96  "  " 

"          "  "  18  "  84.90  "  " 

"              "  "  20  ll  60.00  "  " 

"  "  40  "  40.54  "  " 

«               cc  cc  «  cc  cc 


The  effective  size  is  No.  59. 
Uniformity  coefficient  is  2.95. 

All  the  valves  for  the  operation  of  the  purification  works  as 
well  as  of  the  pumping  machinery,  of  which  there  are  15,  are 
within  easy  reach  of  the  engineer  from  the  engine-room  floor; 
the  only  outside  valves  are  the  two  ejector  valves  beneath  the 
roof  of  the  filters.  The  boilers  face  the  engine-room  and  can 
be  continuously  under  the  eye  of  the  engineer. 

Both  the  Richmond  and  the  Liberty  water-supply  works  are 
operated  by  one  attendant  except  at  the  time  of  scraping  the 
filters,  when  the  attendant  of  the  Richmond  works  requires  a 
helper  because  the  lack  of  facilities  for  mechanically  removing 
the  sand  and  for  storing  it  on  the  roof  of  the  filters.  These  have 
been  supplied  in  the  Liberty  works.  The  subsiding  basin  of 
the  Richmond  works  admits  of  water  softening. 

The  entire  process  by  which  the  water  of  both  works  is  puri- 
fied is  entirely  a  natural  process  and  is  so  simple  that  the  ordinary 
water-works  attendant  has  no  difficulty  in  conducting  all  the 


H2  WA  TER-SUP PLIES. 

operations  successfully  without  the  aid  of  skilled  assistance  except 
for  a  few  days  when  the  purification  works  are  first  started,  and 
then  only  to  teach  the  attendant  the  principles  and  the  few 
mechanical  restrictions  under  which  the  purification  works  should 
be  operated. 

The  hygienic  quality  of  the  water  which  is  the  product  of 
such  purification  works  as  the  two  just  described  is  of  the  highest 
rank.  The  aeration  which  the  ground-water  receives  not  only 
oxidizes  the  iron  but  also  substitutes  air  for  the  gases  so  often 
present  in  an  iron  water.  Filtration  imparts  to  it  a  clearness 
which  is  always  delightful  in  a  drinking-water  and  a  perfect  free- 
dom from  the  inky  taste  of  the  fresh  well-water.  In  fact  there  is 
so  complete  a  transformation  of  the  hygienic  qualities  of  the 
water  in  passing  from  the  well  through  the  aerator  and  filter 
to  the  clear-water  basin  that,  so  far  as  one  may  base  a  judgment 
upon  taste  and  appearance,  they  are  waters  of  totally  different 
characteristics,  and  the  same  statement  may  be  made  of  the  water 
with  regard  to  many  domestic  uses.  The  method  of  purifying  the 
water  leaves  no  room  for  the  suspicion  of  the  presence  of  unpleas- 
ant or  undesirable  by-products  of  chemical  treatment  which  so 
often  attaches  to  the  water  from  filters  or  settling-basins  which 
perforce  must  use  a  coagulant  to  remove  the  sediment  from 
surface-water.  In  the  one  instance  the  chemical  action  result- 
ing in  the  oxidation  of  the  iron  is  altogether  natural  and  diminishes 
the  amount  of  both  mineral  and  organic  matter  present  in  the 
fresh  well-water,  while  in  the  other  instance  the  use  of  the  coagu- 
lant adds  to  the  dissolved  mineral  of  the  raw  water  and  also  some- 
times leaves  suspended  in  a  clarified  river-water  a  portion  of  the 
coagulant  in  a  hydrated  form. 

No  possible  exception  can  be  taken  to  the  bacterial  purity  of 
filtered  iron  water,  for  could  any  suspicion  whatever  attach  to 
the  well-water  naturally  filtered,  the  suspicion  is  entirely  elimi- 
nated by  the  second  process  of  filtration  in  covered  filters  and 
the  subsequent  storage  of  the  doubly  filtered  water  in  a  covered 
storage  basin.  No  artificially  filtered  surface-water  can  surpass 
the  doubly  filtered  well-water  in  hygienic  or  bacterial  purity. 
Moreover,  the  filtered  iron  water  approaches  more  nearly  the 
popular  conception  of  a  desirable  drinking-water  than  any  puri- 


GROUND-WATER  SUPPLY.  113 

fied  surface-water  can  approach  such  a  quality,  and  therefore, 
in  small  towns  particularly,  is  the  more  readily  accepted  as  a 
substitute  for  the  neighborhood  spring,  the  private  well,  or  even 
the  cistern,  while  in  large  towns  its  advent  as  a  hygienic  water 
would  be  hailed  with  an  expression  of  the  most  genuine  approval 
and  indorsement  from  every  side.  With  large  towns  the  only 
questions  to  be  considered  in  connection  with  the  development 
and  purification  of  a  ground- water  impregnated  with  iron  are 
the  ones  of  quantity  and  adaptability  to  mechanical  uses.  The 
quantity  is  unquestionably  large  in  such  valleys  as  those  of  the 
Missouri,  Mississippi,  Platte,  and  Kansas  Rivers,  where  there  is 
unquestionably  river  reinforcement  to  the  rainfall  feed  of  the 
underlying  gravel-beds.  But  even  though  sufficient  water  may 
not  be  obtained  for  a  full  supply  of  water  of  a  large  city  which 
must  otherwise  depend  upon  purified  river-water  for  its  supply,  a 
partial  supply  of  iron  water  aerated  and  then  mixed  with  that 
portion  of  the  supply  derived  from  the  river  will  through  the 
coagulating  property  of  the  iron  aid  in  the  removal  of  sediments 
as  has  been  pointed  out  in  the  paragraph  Natural  Coagulation 
of  the  chapter  entitled  River-water  Supply.  Sometimes  the 
mixture  of  different  waters  supplies  food  for  the  natural  micro- 
scopic life  contained  therein,  and  accordingly  aquatic  life  may  de- 
velop luxuriantly  and  upon  dying,  after  the  consumption  of  the 
food-supply,  give  to  the  waters  an  offensive  odor  and  taste.  This 
trouble  need  not  be  feared  when  the  mixed  waters  are  stored 
in  the  small  storage  basins  of  purification  works,  for  there  is  not 
sufficient  time  for  its  development. 

Ground- water  is  evidently  more  desirable  hygienically  than 
impure  surface-water  which  requires  clarification  and  purification, 
whether  it  is  usable  directly  as  removed  from  the  ground  or  re- 
quires previous  treatment  to  remove  objectionable  minerals;  besides 
when  ground-water  must  be  treated,  the  works  and  plant  required 
for  this  treatment  are  always  more  condensed,  less  expensive,  and 
require  less  skilled  supervision  in  operation  than  the  purifica- 
tion works  needed  for  the  purification  of  muddy  and  impure 
surface-water.  It  frequently  pays  a  city  to  go  a  long  distance 
to  secure  that  sort  of  water-supply  rather  than  to  install  purifi- 
cation works  to  cleanse  a  nearer  but  impure  surface-water.  The 


H4  WATER-SUPPLIES. 

natural  facilities  in  this  direction  are  not  confined  to  the  require- 
ments of  small  cities  and  towns,  but  by  proper  forms  of  develop- 
ment they  may  be  made  available  for  cities  of  considerable  size. 

It  will  certainly  pay  any  city  to  make  thorough  investigation 
of  the  availability  of  ground-water  in  its  vicinity  before  grappling 
with  the  highly  expensive  problem  of  surface-water  purification, 
for  expensive  construction  and  maintenance  must  precede  success- 
ful and  satisfactory  operation  of  purification  works. 

A  zeal  to  stimulate  the  growth  of  high  ideals  as  to  what 
constitutes  a  standard  of  hygienic  purity  and  to  give  struc- 
tural expression  to  these  high  ideals  should  not  lead  one  to 
such  extreme  lengths  as  to  claim  for  the  purification  works  which 
depend  upon  ceaseless  vigil  for  efficiency  of  action  the  loftiest 
structural  expression  of  such  ideals,  but  rather  influence  one  to 
accept  such  works  as  desirable  and  necessary  only  in  the  absence 
of  means  and  facilities  of  obtaining  structural  expression  in  a 
simpler,  more  direct,  and  less  expensive  form,  wherein  skilled 
surveillance  is  reduced  to  a  minimum  because  of  the  fact  that 
the  source  from  which  the  water-supply  is  derived  is  either 
unpolluted  or  so  surrounded  by  natural  safeguards  as  to  render 
artificial  pollution  a  remote  probability  or  even  a  bare  possi- 
bility. All  energetic  efforts  towards  progress  tend  to  develop  a 
few  extremists  either  in  fact  because  of  their  extremely  optimistic 
or  visionary  views,  or  so  called  because  their  energy  and  fore- 
sight keep  them  well  in  advance  of  the  general  procession.  A 
switch  to  by-roads  from  the  general  direction  of  progress,  reac- 
tion, retrograde  movement,  a  return  to  the  old  but  newly  paved 
and  better-lighted  route,  a  renewed  advance  are  the  accompani- 
ments of  general  progress  in  technical  as  well  as  in  other  every- 
day pursuits. 

Thus  upon  the  opportunities  of  a  community  to  learn  of  and 
appreciate  progress,  upon  its  means  as  well  as  upon  its  needs, 
depends  very  much  the  perfection  of  water-supply  development 
in  individual  cases.  Often  simple  though  fairly  effective  methods 
of  water-supply  may  lead  to  a  quicker  and  better  appreciation 
of  high  ideals  of  hygienic  purity  than  more  complex  methods 
which  require  the  exercise  of  special  skill  in  the  attainment  of 
good  results.  Accordingly  clear  and  wholesome  natural  water 


GROUND-WATER  SUPPLY.  H5 

either  at  or  below  the  surface  of  the  ground  is  of  first  considera- 
tion, ground-water  treated  when  necessary  to  improve  its  quality 
for  general  use  is  of  the  second  rank,  and  artificially  purified 
surface-water  should  be  acceptable  in  the  absence  of  facilities 
for  obtaining  either  of  the  former  grades  of  water-supply  econ- 
omically or  in  sufficient  quantity. 


CHAPTER  II. 
RIVER-WATER  SUPPLY. 

RIVERS  usually  constitute  a  frequent  and  unfailing  source 
of  water-supply  and  are  probably  more  in  demand  for  this  pur- 
pose in  the  central  and  southern  portions  than  in  any  other  sec- 
tions of  the  country.  But  it  is  seldom  that  the  river-water  can 
be  used  without  some  sort  of  purification.  Purification  works 
add  much  to  the  expense  of  the  construction,  maintenance,  and 
operation  of  a  system  of  water- works,  and  when  successfully 
operated  demand  no  small  amount  of  attention  from  the  manage- 
ment and  attendants.  In  the  East,  sewage  and  manufacturing 
wastes  constitute  the  chief  source  of  river  pollution,  while  in 
the  Middle  West,  where  these  sources  of  pollution  are  relatively 
less,  there  is  an  exceedingly  large  amount  of  sediment  carried 
in  suspension  by  nearly  all  rivers  and  streams  which  needs  to 
be  removed.  Problems  of  water  purification,  while  having  the 
same  object  in  view  in  all  sections  of  the  country,  receive  solu- 
tion in  a  manner  differing  very  much  in  the  mechanical  details 
of  the  purification  works.  For  instance,  the  filter  is  usually 
considered  the  essential  requirement  for  removing  sewage  pollu- 
tion, and  the  settling-basin  or  a  combination  of  the  settling- 
basin  and  filter  for  clarifying  muddy  water. 

In  order  to  present  the  practical  side  of  the  several  methods 
of  water  purification,  it  is  necessary  to  pursue  the  description 
considerably  in  detail,  particularly  that  portion  of  the  descrip- 
tion relating  to  the  preliminary  treatment  of  river-water  in 
preparing  it  for  filtration. 

Clarification  alone  is  necessary  when  a  naturally  muddy 
water  can  be  made  wholesome  by  removing  the  sediment  which 
it  contains.  This  is  frequently  accomplished  by  the  use  of  the 

116 


RIVER- WATER  SUPPLY.  II; 

settling-basin.  But  when  the  purity  of  the  water  aside  from 
the  sediment  which  it  may  contain  is  in  question,  the  water 
must  be  subjected  to  some  additional  treatment  before  it  can 
be  considered  wholesome.  The  additional  treatment  usually 
consists  of  sand  nitration  or  the  use  of  a  germicide  either  to 
remove  the  bacteria  infesting  the  water  or  to  kill  them  outright 
by  the  toxic  effect  of  some  applied  chemical.  The  essential  ob- 
ject to  be  accomplished  in  either  case  is  the  removal  of  objection- 
able bacteria  that  may  have  entered  the  source  of  water-supply 
with  any  sewage  discharging  into  the  source  from  which  the 
supply  is  taken. 

There  is  no  sharp  dividing  line  between  the  process  of  simple 
clarification  and  that  of  bacterial  purification  of  a  water,  par- 
ticularly when  the  natural  water  contains  much  finely  divided 
clay  in  suspension;  for  then  the  process  which  is  necessary  to 
secure  a  complete  clarification  artificially  will  often  relieve  the 
water  of  bacterial  life  to  such  a  degree  as  to  render  it  safe  and 
wholesome.  In  showing  the  difference  between  a  process  of 
simple  clarification  and  one  of  purification  as  now  practiced, 
it  is  necessary  to  follow  out  the  present  methods  of  treating 
muddy  water  somewhat  systematically  and  in  detail. 

Settling-basins.  —  The  settling-basin  as  a  factor  in  water 
clarification  has  received  its  most  extensive  development  in 
cities  along  the  Missouri  and  Mississippi  Rivers.  Here  the  com- 
mon practice  for  years  has  been  to  depend  upon  sedimentation 
for  clarification.  Accordingly  the  basin  is  usually  divided  into 
at  least  four  divisions,  each  division  having  a  capacity  for  water 
of  about  one  day's  consumption.  Two  distinct  methods  of 
operating  the  basin  are  followed:  one  is  termed  the  fill-and- 
draw  method,  the  other  the  continuous-flow  method,  the  water- 
supply  being  abstracted  after  subsidence  from  each  of  the  four 
divisions  in  the  former  method  and  continuously  from  a  single 
division  in  the  latter  method. 

The  fill-and-draw  method  embraces  a  period  of  uninter- 
rupted rest  of  the  water  in  one  division  of  the  basin  while  the 
day's  supply  is  being  abstracted  from  another  division,  while 
a  third  division  is  being  filled,  and  while  a  fourth  division  is 
being  cleaned.  A  serious  and  practically  insurmountable  diffi- 


Il8  WATER-SUPPLIES. 

culty  in  this  method  of  operation  is  the  one  of  drawing  upon 
the  division  containing  the  subsided  water  for  any  large  per- 
centage of  the  contained  water  without  disturbing  and  drawing 
into  the  effluent  pipe   a  considerable   portion   of   the  intensely 
muddy  lower  water  which  has  grown  dense  with  deposits  from 
above.     The  sediment  descends  very  slowly  through  the  lower 
water  before  final  repose  in  a  compact  form  at  the  bottom  of 
the  basin,  and  when  in  this  semi-fluid  state  it  is  very  unstable 
and  naturally  mingles  with  the  less  turbid  water   from   above 
as  it  eddies  into  the  effluent  pipe.      Even  a  more  serious  objec- 
tion to  the  fill-and-draw  plan   of   operation   is  the   one   that   a 
river-water  does  not  respond   equally   on   each   and   every   day 
to  the  process  of  natural    sedimentation,   as  the   amount   and 
character  of  the  sediment  in  river-water  varies  or  as  the  tem- 
perature changes.    Within  a  single  day  the  water  in  a  settling- 
basin  operated  on  this  plan  may  change  from  one  slightly  turbid 
to  one  decidedly  muddy   and   opaque.     Moreover,  a  coagulant 
when  needed  must  be  introduced  into  the  raw  water  as  taken 
from  the  river  by  the  pumps,  and  when  so  introduced  much  of 
it  is  absorbed  or  subsides  with  the  heavy  sediment,  leaving  the 
fine   sediment  practically   unaffected  by   the   process   of  coagu- 
lation except  when  the  coagulant  is  used  in  excess.     The  objec- 
tions  mentioned   are   so   serious   that    the   settling-basins   orig- 
inally constructed  to  operate  on  the  fill-and-draw  plan  are  grad- 
ually being  remodeled  to  operate  on  the  continuous- flow  plan. 

The  continuous- flow  method  of  sedimentation  provides  for 
the  passage  of  the  water  from  one  division  of  the  basin  to  another 
successively,  the  muddy  water  being  introduced  into  the  first 
division  of  the  series  and  the  clarified  water  being  stored  and 
abstracted  from  the  last  division  of  the  series.  Progressive  sedi- 
mentation takes  place  during  the  interval  of  transit  from  division 
to  division. 

The  simplest  method  of  communication  with  the  series  of 
divisions  of  the  settling-basin  is  by  long  depressions  or  weirs 
in  the  division  walls,  together  with  suitable  by-pass  pipes  or 
conduits  to  facilitate  the  emptying  and  cleaning  of  any  one  of 
the  divisions  without  disturbing  the  operation  of  the  other  divi- 
sions of  the  series. 


RWER-IVA7ER  SUPPLY. 


119 


The  water  upon  entering  a  division  of  the  basin  near  the  bot- 
tom displaces  an  equal  amount  of  clearer  water  at  the  surface 
which  passes  to  the  succeeding  division  over  a  weir  in  a  division 
wall.  The  weir  method  of  communication  between  the  basin 
divisions  insures  a  transfer  of  the  clearest  water,  which  is  always 
near  the  surface,  and  the  least  interference  with  the  process  of 
sedimentation.  This  may  properly  be  termed  the  displacement 
principle  of  the  continuous-flow  method. 

The  weirs  may  or  may  not  be  constructed  the  entire  length 
of  a  division  wall  of  a  basin,  the  object  sought  being  to  convey 


Drain 


Gutter 


inlet 
Well 


FIG.   15. — Settling-basin  with  Baffles. 

the  water  from  one  division  of  the  basin  to  another  in  a  thin 
sheet  that  serves  to  skim,  as  it  were,  the  surface-water.  The 
coldest  winter  weather  does  not  cause  any  interference  of  ice 
at  any  weir,  as  the  water  emerges  from  under  the  ice  on  one  side 
of  the  division  wall,  flows  over  the  wall  at  a  temperature  slightly 
above  freezing,  and  disappears  beneath  the  ice  on  the  oppo- 
site side  of  the  wall. 

A  method  employed  to  avoid  a  tendency  to  surface  currents 
as  the  water  passes  from  the  weir  is  to  suspend  vertically  a  cur- 
tain of  planks  about  two  inches  from  the  weir.  The  curtain 
deflects  the  water  downward  to  any  desired  depth. 

A  modification  of  the  displacement  principle  of  continuous- 
flow  is  to  be  found  in  the  use  of  a  settling-basin  supplied  with 
baffle-walls  instead  of  division  walls.  These  baffle-walls  guide 
the  water  by  a  circuitous  route  through  a  single  compartment 


120 


WATER-SUPPLIES. 


basin  upon  the  theory  that  the  flow,  although  continuous,  is  at  so 
low  a  velocity  that  sedimentation  is  progressive  during  the  forward 
progress  of  the  water.  An  illustration  of  this  principle  is  shown 


[TfpElev.  Concrete  Surface  9S..5 
I  Basin  2 


\  1 1  j   Ij  Bedded  in  Concrete      \^ 


FIG.  16. — Plan  of  Settling-basin. 

on  Fig.  15,  a  sedimentation  basin  designed  for  Fort  Smith,  Ar- 
kansas, in  1896  by  the  author.  The  water  enters  one  end  of  the 
basin,  swings  around  the  several  baffle-walls,  which  are  built 
to  the  same  elevation  as  the  top  of  the  basin  enclosing  walls, 
and  discharges  into  a  receiving-well  at  the  opposite  end  of  the 


RIVER- WA7ER  SUPPLY. 


121 


basin  in  a  thin  sheet  over  the  well-rim.  Although  this  struc- 
ture has  never  been  built,  it  serves  to  demonstrate  the  principle 
upon  which  baffles  are  supposed  to  work  in  horizontal  flow.  A 
modification  of  this  principle  can  readily  be  made  to  produce  a 
flow  in  a  vertical  plane. 

Settling-basins  having  but   one  or   two  divisions  are  some- 


la'Inrtuent  Pipe  from 
Low  Pressure  Pump 

H'Suction  to 
High  .Pressure  Pump 


FIG.   17. — Plan  of  a  One-division  Settling-basin. 

times  operated  on  the  displacement  method,  as  shown  by  Figs. 
16,  17,  and  18. 

Fig.  1 6  shows  a  water-purification  works  consisting  of  a 
two-compartment  subsiding-basin  and  a  mechanical  filter-plant. 
The  raw  river- water  enters  division  i,  displacing  an  equal  volume 
of  water  which  passes  into  division  2  over  a  weir,  swings  through 
division  2,  and  finally  passes  over  the  arch  wall  in  the  corner  of 
division  2  into  the  effluent  well,  whence  it  passes  to  the  mechanical 


122 


WATER-SUPPLIES. 


filters.  During  the  process  of  cleaning  either  one  of  the  two 
divisions  of  the  basin  the  other  division  can  be  operated  singly 
in  connection  with  the  effluent  well. 

A   three-division   basin    (not   constructed)    operated   on    the 
displacement  plan  is  shown  in  Fig.  19.    The  principle  of  opera- 


tion of  this  basin  is  similar  to  that  of  the  two-division  basin  just 
described,  except  for  such  modification  of  operation  as  is  em- 
braced in  a  three-division  layout. 

Other  designs  of  settling-basins  are  to  be  seen  on  succeeding 
figures  which  accompany  descriptions  on  other  pages  of  this 
chapter. 


RIVER-WATER  SUPPLY. 


123 


Natural  Subsidence. — -When  a  muddy  water  is  delivered 
into  a  settling-basin  operated  either  by  the  fill-and-draw  method 
or  by  that  of  continuous-flow,  sediment  naturally  settles  to 
the  bottom  and  the  water  becomes  clarified  to  a  degree.  This 


30  *  Pipe  from  Reservoir  to  Pump  Well         % 
•^=-=-w--.=r=-..".:  -  - ; —  == ^:-  - v=--=s=rg/ 


method  of  clarification  is  termed  natural  or  plain  sedimentation 
to  distinguish  it  from  the  method  of  sedimentation  with  the 
aid  of  a  coagulant. 

The  degree  of  clarification  which  can  be  attained  by  natural 
sedimentation  depends  upon  the  character  of  the  sediment  in 
the  raw  water  and  to  a  degree  upon  the  viscosity  of  the  water 
itself.  A  sediment  composed  almost  wholly  of  sand  descends 


124 


WATER-SUPPLIES. 


rapidly  and  a  fair  degree  of  clarification  may  be  reached  by  natu- 
ral sedimentation.  A  raw  water  of  this  class  is  characteristic 
of  the  Missouri  River  during  the  late  summer  and  the  fall  months, 
when  the  sediment  carried  in  suspension  is  largely  sand  with 
a  small  percentage  of  clay. 

When  a  considerable  amount  of  clay  is  carried  in  the  water, 
there  is  always  a  portion  of  it  which  is  so  finely  divided  and  so 
light  that  it  resists  natural  subsidence  for  a  long  period,  even 
for  a  longer  period  than  admits  of  satisfactory  clarification  in  a 
settling-basin  containing  four  to  six  times  the  daily  consumption 
of  water.  This  is  the  condition  of  the  Missouri  River  water  in 
the  spring  of  the  year  and  of  almost  any  other  detrital  rivers 
of  the  middle  West  during  either  all  or  a  portion  of  each  year, 
depending  upon  the  character  of  the  soil  in  the  territory  drained. 

Robert  Spurr  Weston,  resident  expert  of  the  Sewerage  and 
Water  Board  of  New  Orleans,  Louisiana,  gives  265  parts  per 
million  of  suspended  matter  remaining  in  the  Mississippi  River 
at  that  city  after  seventy-two  hours'  natural  subsidence. 

In  the  Cincinnati  experiments  conducted  by  George  W.  Fuller 
for  the  purification  of  the  Ohio  River  water,  Mr.  Fuller  tabu- 
lates results  of  natural  subsidence  as  follows: 

TABLE  I. — SUSPENDED  MATTER  IN  OHIO  RIVER. 
(In  parts  per  million.) 


Range. 

Original. 

After  7  2  hours  of 
plain  subsidence. 

Percentage 
removed. 

I  to  50              ... 

^8 

I  2 

68 

51  to  100    

7  3 

I  0 

74. 

IOltO25O  

166 

48 

7  I 

251  to  500  

33O 

Q? 

72 

501  to  1000  

665 

184 

72 

1000  and  over  

12  ^  C 

222 

82 

In  some  observations  of  sedimentation  of  Missouri  River 
water  the  results  are  as  shown  by  Table  II. 

The  observations  in  this  table  were  made  of  water  passing 
through  the  settling-basin  of  the  Kansas  City,  Missouri,  water- 
works, illustrated  by  Fig.  20.  Observations  after  a  longer  period  of 
natural  sedimentation  could  not  be  recorded,  as  the  water  received 
a  coagulant  solution  immediately  after  twenty-four-hours '  natural 


RIVER-WATER  SUPPLY. 


sedimentation.  There  were  occasions,  however,  before  a  sys- 
tematic method  of  coagulation  was  introduced  when  the  water 
was  completely  opaque  and  must  have  contained  several  hun- 
dred parts  per  million  of  sediment  after  fully  four  days'  expo- 
sure to  natural  subsidence. 

TABLE  II. 
(In  parts  per  million.) 


Date. 

Suspended  matter. 
River-water. 

Suspended  matter  in 
River-water  after 
about  24  hours'  natural 
subsidence. 

Suspended  matter 
removed  bv  natural 
subsidence. 
Per  Cent. 

January  18,   1900 

20 

650 

80 
100 

87   7 
80.6 

24 
26 
March       10 

12 

14 

490 

2315 
2520 

2OOO 
I  I  60 

140 

50 

325 
470 

295 

714 
90-3 
93-5 
87.1 

76.5 
74-6 

Average.. 

2O2 

82.7 

At  St.  Louis,  where  plain  or  natural  sedimentation  has  been 
practiced  for  a  number  of  years,  the  results  are  expressed  in 
the  following  table. 

TABLE  III. 


Period. 

Average  sedi- 
ment in  raw 
water,  parts 
per  million. 

Average  period 
of  subsidence. 
Hours. 

Sediment  in 
subsided  water, 
in  parts  per 
million. 

Per  cent  of 
sediment 
mo\ed. 

Bissell's  Point, 
1885-86 

1186 

24. 

I  O4. 

OI 

Bissell's  Point, 
1887-88 

1186 

34* 

3O< 

•JA 

Chain  of  rocks, 
1900—1    

1152 

60 

I65 

86 

In  the  experiments  at  Louisville  with  the  Ohio  River  water 
the  average  of  five  experiments  was: 

Parts  per  million. 
Suspended  matter 469 

Sediment  in  subsided  water,  24  hours'  settlement       277 
' "       48      "  "  155 


126 


WATER-SUPPLIES. 


The  per  cent  of  sediment  removed  is  about  41  per  cent  for 
twenty-four  hours'  and  67  per  cent  for  forty-eight  hours'  natural 
sedimentation. 

The  remnant  of  the  sediment  still  suspended  in  the  water- 
after  natural  sedimentation  is  probably  of  the  same  general 


character  in  each  instance  referred  to,  as  the  average  amount 
of  this  remnant  does  not  vary  much  in  any  of  the  river-waters 
named.  A  greater  variation  may  be  found  by  comparing  the 
results  of  natural  sedimentation  of  the  several  river- waters  at 
seasons  of  the  year  when  turbidity  is  most  persistent. 

Sedimentation  is  slower  in  the  spring  of  the  year  when  the 


RIVER-WATER  SUPPLY.  127 

water  is  chilled  because  of v  the  greater  viscosity  of  the  water  at 
this  season  of  the  year.  There  is  no  practical  way  of  remedy- 
ing this  difficulty. 

It  is  evident  from  what  precedes  that  natural  sedimentation 
is  not  an  effective  means  of  thoroughly  clarifying  muddy  river, 
water,  although  it  is  a  very  effective  method  of  removing  the 
heavy  sediment  which  is  simply  held  in  suspension  by  the  com- 
plex motion  of  a  flowing  river.  The  remnant  of  sediment  in  a 
naturally  subsided  water  may  amount  to  as  much  as  i  cubic 
yard  for  each  1,000,000  gallons  of  water  or  even  more. 

The  result  of  natural  sedimentation  for  clarifying  a  public 
water-supply  taken  from  a  detrital  river  has  been  found  efficient 
in  no  city  which  has  thus  far  tried  the  process,  but  notwithstand- 
ing the  fact  that  natural  sedimentation  has  its  limitations  and 
is  a  failure  in  the  regard  stated  it  has  its  proper  and  necessary 
place  in  the  art  of  water  clarification. 

Circulation. — Phenomena  which  are  apparent  in  a  large  set- 
tling-basin may  be  absent  in  an  experimental  plant  because  of 
the  impracticability  of  duplicating  in  a  small  way  all  the  condi- 
tions which  affect  the  circulation  of  water  in  a  large  settling- 
basin.  Many  of  the  author's  observations  recorded  in  this  chapter 
were  made  while  conducting  experiments  on  a  small  scale  and 
while  supervising  the  operation  of  the  Quindaro  settling-basin 
of  the  Kansas  City,  Missouri,  water-works.  A  plan  of  the  Kansas 
City  basin  is  shown  by  Fig.  20.  It  is  about  20  feet  deep  at  the 
division  walls,  and  as  originally  designed  by  G.  W.  Pearson, 
division  No.  I  of  the  basin  was  the  receiving-basin  of  the  raw 
water.  The  water  entering  the  basin  through  a  rising  pipe  and 
a  well  about  4  feet  high,  impinged  against  an  inverted  conical 
deflector  which  caused  the  water  to  spread  horizontally  in  all 
directions.  In  1899  the  influent  pipe  was  extended  across  divi- 
sion i  and  was  made  to  deliver  the  raw  water  into  a  conduit  in 
the  wall  separating  divisions  i  and  2,  through  which  it  -flowed 
to  openings  at  the  foot  of  the  vertical  wall  of  the  straight  side 
of  the  basin  and  discharged  laterally  into  division  2.  The  object 
of  this  change  was  to  make  division  i  a  clear- water  basin,  as  it 
had  become  too  small  to  work  successfully  as  a  raw-water  basin 
when  the  rate  of  delivery  into  it  exceeded  6  to  8  million  gallons 


128 


WATER-SUPPLIES. 


a  day.  Modifications  were  also  made  of  the  manner  of  passing 
the  water  from  one  division  of  the  basin  to  another  at  about 
the  same  time  as  the  change  above  noted  was  made.  As  origi- 
nally designed  the  water  passed  from  one  division  of  the  basin 
to  another  through  conduits  and  openings  constructed  in  the 
division  walls,  the  water  entering  openings  near  the  top  on  one 
side  of  a  division  wall  and  discharging  into  an  adjoining  basin 


£  Round ^ 

2-1  tf \Anchor  Rod 


SECTION  OF  BUTTRESS 

OF 
WALL  BETWEEN  BASINS  3  AND  4 

FlG.    21. 

through  similar  openings  at  the  foot  of  a  division  wall.  The 
water  'circulates  on  the  modified  plan  by  overflowing  a  portion 
of  a  division  wall.  The  water  from  division  2  flows  into  division  3 
over  a  weir  in  the  division  wall  133  feet  long.  In  a  similar  man- 
ner the  water  passes  into  division  4  from  division  3  over  a  weir 
in  the  wall  between  divisions  3  and  4, 185  feet  long,  shown  in  sec- 
tion by  Fig.  21.  From  division  4  the  water  enters  division  i 


RIVER-WATER  SUPPLY.  129 

through  a  conduit  in  the  straight  side  wall.  Provision  is  also 
made  for  delivering  the  influent  water  into  any  one  of  the  three 
large  divisions  while  some  one  of  these  divisions  is  temporarily 
out  of  service.  Plates  XVI,  XVII,  and  XVIII  show  an  eleva- 
tion of  the  weirs  in  the  division  walls. 

The  effluent  well  remaining  as  originally  designed  is  a  con- 
duit in  the  bottom  of  the  circular  wall  between  divisions  i  and  3, 
extending  from  the  inlet  tower  to  the  large  buttress  of  the  cir- 
cular wall  between  divisions  i  and  4.  It  connects  with  divi- 
sions i,  3,  and  4. . 

In  operating  a  settling-basin  on  the  displacement  plan  the 
influent  water  should  be  delivered  horizontally  near  the  bottom 
of  the  basin  in  order  to  avoid  as  much  as  possible  a  tendency 
to  upward  vertical  motion  and  to  favor  a  dispersion  of  the  enter- 
ing water,  conforming  to  a  temperature  contour. 

The  entering  water  when  thus  introduced  distributes  laterally 
over  the  basin  without  rising  to  the  surface.  This  fact  has  been 
observed  upon  numerous  occasions  by  comparing  samples  of 
water  from  various  depths  and  from  various  portions  of  the 
division  receiving  the  raw  river-water.  For  a  considerable  depth 
the  turbidity  is  about  uniform,  then  slightly  increases,  and  finally 
there  is  a  decidedly  abrupt  change  from  turbidity  to  intense 
muddiness.  The  variations  of  the  depth  of  the  mud  plane  appear 
uniformly  distributed  throughout  the  entire  division  receiving  the 
raw  water,  except  when  the  entering  water  is  abruptly  de- 
flected upward  near  the  delivery  openings,  where  the  heavy 
sediment  is  chiefly  deposited.  Below  this  mud  plane  there  is  a 
thick  fluid  mud  which  apparently  increases  in  density  until  the 
solidified  deposit  on  the  bottom  is  reached.  As  the  deposit 
accumulates,  the  level  of  the  mud  plane  rises  and  eventually 
mud  streaks  the  overflow  into  the  succeeding  basin,  indicating 
the  approach  of  cleaning  time.  However,  the  working  life  of 
the  raw-water  division  may  be  somewhat  prolonged  by  discharging 
a  portion  of  the  liquid  mud  through  the  drain.  The  working 
of  a  settling-basin  on  the  displacement  plan  continues  satisfac- 
torily until  the  basin  becomes  foul  or  overtaxed,  or  until  vertical 
currents  are  induced  by  a  sudden  and  injudicious  increase  of 
the  rate  of  delivery  of  river-water  into  the  basin,  or  until  a  rapid 


130 


WATER-SUPPLIES. 


u 


n — 

U 


RIVER- WATER  SUPPLY. 


WATER-SUPPLIES. 


RIVER-WATER  SUPPLY.  133 

building  up  of  the  heavy  sediment  near  the  influent  openings 
deflects  the  entering  water  abruptly  upward. 

The  author's  attention  was  early  directed  to  the  theory  of 
displacement  as  producing  the  continuous  flow  of  water  from 
one  division  of  a  settling-basin  to  another  by  observations  of  the 
tendency  of  the  water  entering  a  settling-basin  to  stratify  accord- 
ing to  a  temperature  contour.  Turbidity  observations  made  of 
the  raw-water  division  of  the  Kansas  City  settling-basin  showed 
that  there  existed  at  the  time  of  one  series  of  observations  but 
slight  difference  in  the  degree  of  turbidity  for  the  first  13  feet 
in  depth  and  almost  a  uniform  degree  of  turbidity  for  the  first 
5  feet,  even  over  the  influent  apertures.  The  transition  from 
a  state  of  turbidity  to  one  of  dense  muddiness  was  sudden  and 
pronounced  below  the  13-foot  level.  Other  observations  of  the 
same  kind  at  different  times  demonstrated  similar  conditions 
with  the  mud  plane  at  a  quite  uniform  level,  though  of  a  varying 
depth  from  week  to  week. 

It  was  also  observed  when  a  division  of  the  basin  was  empty 
for  cleaning  that  the  solidified  fine  mud  was  quite  uniformly 
distributed  over  the  bottom,  sometimes  exhibiting  a  stratifica- 
tion of  different  shades,  while  the  heavy  sediment  was  found 
to  form  a  comparatively  high  embankment  in  the  vicinity  of  the 
inlet  opening. 

When  pumping  machinery  is  employed  to  deliver  the  raw 
water  into  a  settling-basin  a  thoughtless  attendant  will  occa- 
sionally speed  the  pumps  unduly,  with  the  effect  of  abruptly  chang- 
ing the  rate  of  delivery  and  of  unbalancing  the  adjustment  of 
lateral  circulation.  The  increased  energy  thus  communicated 
to  the  water  often  induces  convection  currents  which  give  an 
upward  circulation  of  water  above  the  mud  plane  established 
by  the  previous  regime  of  pumping  and  circulation,  with  a  cor- 
responding infusion  of  intensely  muddy  water  into  the  partially 
clarified  water  of  the  upper  depths  of  the  basin.  The  convection 
currents  readily  climb  the  faces  of  the  enclosing  walls  and  slopes 
of  a  basin  and  diffuse  laterally  therefrom. 

The  tendency  of  water  to  stratify  is  very  marked  during  the 
summer  and  autumn  seasons  when  the  temperature  of  the  air 
is  either  comparatively  steady  or  subject  to  gradual  change. 


134 


WATER-SUPPLIES. 


Then  the  upper  layers  of  the  water  in  the  basin  reach  a  tem- 
perature above  that  of  the  river-water,  and  the  entering  river- 
water,  responding  to  the  law  of  gravity,  naturally  seeks  the  lower 
depths  and  a  lateral  distribution  in  the  basin  corresponding  to 
some  temperature  contour.  Doubtless  this  stratification  of  the 
water  accounts  for  the  existence  of  the  mud  plane  referred  to  on 
preceding  pages. 

At  other  seasons,  particularly  the  early  spring  and  the  early 
winter  months,  certain  natural  causes  serve  to  break  in  upon 
the  normal  working  condition  of  the  settling-basin,  producing 
pronounced  convection  currents  which  are  locally  termed  ''boil- 
ing." The  appearance  of  this  boiling  is  not  due  to  any  sudden 
alteration  of  the  regime  of  operating  the  basin,  as  all  divisions 
of  the  basin  may  be  similarly  affected,  though  perhaps  not  in 
the  same  hour  or  day.  Temperature  observations  made  of 
the  water  in  the  Kansas  City  settling-basin  revealed  tempera- 
ture conditions  at  different  depths  of  the  basin  indicated  by 
Table  IV. 

TABLE  IV. 


Date. 

Depth  below  water-surface  in  subsiding-basin  in  feet. 

B 

_0 

v-  £ 

I* 

t_ 
t> 

> 

s 

0 

i' 

2' 

3' 

4' 

s' 

6' 

TO' 

II' 

Temperatuie  in  degrees  Fahrenheit. 

June     2    1808 

82 
84 
87 
76 

54 

3£ 
36 

82 

82 

82 

81 

8o£ 

84 
72 

SoJ 

~-J  00  00  00 

H  OJ  K)  O 

MH 

80 
52 

Oo  00 
00  ON 

80 
72 

Tulv    2C,  1808.  . 

Aug    10    1808 

Sept.    8,  1898  
Aor    14.    1800 

Jan.    20,  1900  
Jan     26    1900.  .    . 

In  every  instance  noted  in  the  table  except  that  of  January 
2oth,  the  temperature  observations  were  made  with  the  basin 
in  a  stable  working  condition  and  unaffected  to  any  material 
degree  by  convection  currents.  On  January  15,  1900,  the  divi- 
sions all  exhibited  pronounced  convection  currents,  particularly 
division  3.  In  division  4  much  hydrate  of  alumina  boiled  up 
to  the  surface  of  the  water.  On  January  i6th  the  convection 
currents  had  nearly  abated.  At  that  time  the  surface  tempera- 


R1VER-WA7ER  SUPPLY.  135 

ture  was  35  degrees,  and  the  temperature  was  36  degrees  at  a 
depth  of  15  feet.  On  this  date  the  hydrate  of  alumina  in  divi- 
sion 4  had  largely  disappeared.  On  January  2Oth  the  boiling 
action  was  resumed  in  division  3  and  was  clearly  visible  along 
the  wall  separating  divisions  3  and  4,  along  the  west  embank- 
ment, and  in  various  other  parts  of  the  division.  A  thin  skin  of 
ice  which  had  formed  over  the  basin  during  the  preceding  night 
emphasized  the  appearance  of  the  convection  currents  as  they 
were  revealed  through  the  ice.  The  ascending  mud  and  gray 
hydrate  of  alumina  seemed  to  rise  with  a  rotary  motion  and 
after  contact  with  the  ice  rolled  away  radially  in  a  manner  resem- 
bling the  rotating  smoke  and  steam  blown  from  a  locomotive 
stack  as  it  gradually  rises,  expands,  and  disperses  through  the 
atmosphere. 

Temperature  observations  made  on  that  date  at  the  surface 
and  15  feet  below  the  surface  revealed  a  uniform  temperature 
of  36  degrees. 

Doubtless  the  same  tendency  towards  stratification  exists  in 
the  water  as  in  the  atmosphere.  When  a  break  of  the  stratifi- 
cation ensues,  the  vertical  currents  are  similar  in  both  fluids, 
though  of  course  less  violent  in  water  because  of  its  greater 
weight  and  inertia. 

Numerous  temperature  observations  of  the  kind  indicated  in 
Table  IV  were  made  at  various  times,  but  all  seem  to  indicate  that 
a  fall  of  temperature  of  about  two  degrees  or  more  between  the 
surface-water  and  that  about  10  feet  below  is  necessary  to  pre- 
serve a  stable  working  condition  of  the  water  in  a  basin  operated 
upon  the  displacement  method.  Convection  currents  develop 
frequently  in  the  spring  of  the  year  as  the  ice  in  the  river  breaks 
up  and  moves  out,  but  before  the  ice  in  the  settling-basin  has 
entirely  melted,  as  well  as  in  the  late  fall  or  early  winter  when 
new  ice  is  forming  or  the  surface  of  the  water  in  the  basin  becomes 
chilled,  and  in  this  regard  the  movements  of  the  water  resemble 
the  seasonal  upsetting  of  the  water  in  a  storage  reservoir  or 
in  natural  lakes.  When  vertical  circulation  is  in  progress  the 
upheaval  of  sediment  from  the  deeper  portions  of  the  water  of 
a  settling-basin  temporarily  emphasizes  the  difficulties  of  water 
clarification  by  sedimentation.  Even  a  deep  basin,  although 


136  WATER  SUPPLIES. 

advantageous  in  several  respects,  may  be  no  protection  from 
temperature  convection  currents.  The  use  of  deep  settling- 
basins  has  been  discouraged  because  of  the  expense  of  con- 
structing high  masonry  walls.  This  objection  can  now  be  met 
in  a  measure  at  least  by  the  use  of  reinforced  concrete. 

Surface  currents,  usually  pronounced  when  the  water  passes 
off  a  weir  in  a  division  wall  at  the  water-level  of  an  adjoining 
basin,  may  be  prevented  by  a  curtain  of  planks  set  several  inches 
from  the  face  of  the  division  wall  and  projecting  several  feet 
beneath  the  surface  of  the  water,  thereby  serving  to  improve  cir- 
culation and  to  assist  clarification. 

Baffles  have  been  introduced  in  small  subsiding  basins  to  direct 
the  circulation  of  water,  but  as  simplicity  of  design  and  opera- 
tion is  desirable  in  sedimentation  basins  intended  for  operation 
on  a  large  scale  baffles  complicate  the  operation  and  add  con- 
siderably to  the  expense  of  construction  and  maintenance. 

The  swinging  motion  of  the  water  as  a  body  is  still  another 
form  of  circulation  which  seems  to  be  entirely  independent  of 
those  herein  described.  The  motion  is  so  slow  that  evidence  of 
it  is  to  be  found  rather  in  the  relative  clearness  of  the  water  in 
different  portions  of  any  division  of  a  basin  than  in  any  well- 
defined  visible  movement.  In  the  Kansas  City  basin  the  clear- 
est water  to  be  found  in  either  division  3  or  4  is  in  the  corner 
of  the  divisions  marked  on  Fig.  20  "clearest  water,"  opposite  the 
outside  or  boundary  walls  of  the  basin.  In  this  case  the  water 
after  falling  from  the  weir  seemed  inclined  to  swing  toward  the 
boundary  walls  and  to  clarify  as  it  receded  from  the  weir  and 
finally  to  reach  the  highest  degree  of  clearness  when  it  had  reached 
the  location  of  the  zone  of  the  clearest  water  above  alluded  to. 
The  line  of  separation  of  the  clearest  water  in  the  basin  from 
that  discharged  from  the  weir  is  generally  very  decided  and  dis- 
tinct. What  influence  the  peculiar  form  of  the  basin  referred 
to  may  have  in  producing  this  swinging  motion  has  not  been 
investigated,  but  there  is  every  reason  to  believe  similar  con- 
ditions would  exist  in  a  rectangular  basin  were  the  weirs  of  no 
greater  fraction  of  the  length  of  the  division  walls  than  they 
are  in  this  basin.  It  is  quite  probable,  however,  were  the  weirs 
to  extend  the  whole  length  of  a  division  wall  the  swinging 


RIVER-WATER  SUPPLY.  137 

movement   of    the  water    as    a    body   would   become    less    ap- 
parent. 

It  cannot  be  assumed  that  the  basin  is  effective  only  for  a 
width  equal  to  the  length  of  a  weir  in  a  division  wall  and  that 
the  water  is  dead  in  the  corners  of  a  basin  beyond  the  ends  of 
a  weir,  for  it  has  been  observed  that  a  change  of  turbidity  in 
the  water  falling  from  a  weir  is  followed  by  corresponding  but 
progressive  change  in  all  parts  of  the  division  receiving  the  water, 
even  in  all  the  corners,  showing  that  all  portions  of  the  basin 
are  effective.  The  corner  of  "clearest  water"  is  the  last,  of 
course,  to  fall  under  the  influence  of  any  change,  but  none  the 
less  sure  of  showing  the  degree  of  change  in  the  division  as  a 
whole.  Insistence  upon  a  symmetrical  or  geometrical  figure  of 
a  settling-basin  seems  unnecessary,  and  in  fact  is  frequently 
impossible  owing  to  topographical  or  land  boundary  consider- 
ations, nevertheless  capacity  to  the  fullest  extent  is  serviceable 
or  can  be  made  serviceable  by  proper  design  and  manipulation  of 
the  operating  details. 

Coagulation. — We  have  already  pointed  out  the  inefficiency 
of  natural  sedimentation  to  properly  clarify  water  of  a  detrital 
river.  The  condition  of  the  subsided  water  when  the  beneficial 
effect  of  natural  subsidence  practically  ceases  is  variable,  depend- 
ing upon  the  amount  of  silt  or  finely  divided  clay  the  river-water 
may  carry  in  suspension.  So  great  is  this  variation  that  exposure 
of  a  raw  river-water  to  a  stated  number  of  hours  of  natural  sedi- 
mentation is  found  to  show  a  turbidity  variation  of  considera- 
ble range.  For  instance,  twenty-four  hours'  natural  sedimen- 
tation will  afford  a  much  clearer  water  at  some  seasons  of  the 
year  than  at  other  seasons  and  during  some  periods  of  the  same 
season  than  during  other  periods.  So  deficient  has  natural  sedi- 
mentation been  found  that  the  aid  of  a  coagulant  is  necessary  to 
produce  even  a  fair  degree  of  clarification  on  many  occasions. 
The  amount  of  coagulant  used  varies  with  the  degree  of  turbid- 
ity of  the  naturally  subsided  water.  Thus  far  the  sulphate  of 
alumina  has  been  used  most  extensively  to  facilitate  clarification. 

Clarification  of  the  water  with  the  aid  of  sulphate  of  alumina 
is  both  a  chemical  and  mechanical  process,  and  as  such  it  is 
now  so  well  understood  as  to  scarcely  require  explanation  in 


138  WATER-SUPPLIES. 

this  chapter  were  it  not  that  the  various  allusions  herein  made 
seem  to  require  some  general  explanation. 

The  use  of  a  coagulant  is  for  the  purpose  of  gathering  together 
into  small  masses  the  very  fine  particles  of  silt  and  clay  which  of 
themselves  are  so  light  and  fine  as  to  resist  natural  subsidence 
and  to  thereby  hasten  their  fall  through  the  water. 

The  coagulant  for  successful  use  must  be  harmless  in  its 
effect  upon  the  water  treated,  leaving  its  wholesomeness  unim- 
paired, and  also  cheap  enough  in  the  market  to  be  available  to 
any  community  which  by  force  of  circumstances  may  have  occa- 
sion to  use  it  in  the  clarification  of  the  water-supply.  The  sul- 
phate of  alumina,  when  judiciously  used,  has  been  found  to 
answer  the  requirements  successfully.  Its  properties  and  its 
effect  upon  turbid  waters  have  long  been  known.  As  manufac- 
tured, it  is  a  salt  of  aluminum  composed  of  about  16  to  18  per 
cent  of  alumina,  about  36  to  37  per  cent  of  sulphuric  acid,  and 
about  44  to  46  per  cent  of  water,  together  with  a  small  percent- 
age of  impurities  like  oxide  of  iron,  in  a  chemical  combination 
similar  to  a  combination  of  sulphuric  acid  with  lime  or  mag- 
nesia. In  a  salt  properly  made,  there  should  be  no  free  sul- 
phuric acid.  It  is  highly  soluble  in  water  and  therefore  readily 
made  into  a  solution  of  any  degree  of  strength  up  to  one  of  com- 
plete saturation  of  the  water. 

The  chemical  affinity  of  the  constituents  of  this  salt  is  com- 
paratively weak  and  is  readily  broken  in  the  presence  of  other 
solutions  of  mineral  salts,  such  as  the  bicarbonate  of  lime  and 
magnesia,  and  made  to  assume  new  chemical  combinations  of  a 
more  stable  character.  In  fact  its  use  depends  upon  the  pres- 
ence in  the  water  to  be  treated  of  a  mineral  salt  in  solution  ca- 
pable of  new  chemical  combinations  with  the  applied  solution. 
Many  natural  waters  contain  abundance  of  lime  and  magnesia, 
the  constituents  of  limestone,  which  are  held  in  solution  by 
carbonic  acid,  and  with  these  salts  the  dissolved  sulphate  of 
alumina  readily  enters  into  combination,  forming  sulphate  of 
lime  or  magnesia,  free  carbonic  acid,  and  hydrate  of  alumina. 
The  sulphate  of  lime  or  magnesia  and  the  carbonic  acid  remain 
dissolved  in  the  water,  while  the  hydrate  of  alumina,  being  insoluble 
in  water,  remains  a  floating  though  finely  divided  solid  and 


RIVER-WATER  SUPPLY.  139 

thus  completes  the  essential  chemical  part  of  the  process  of  coagu- 
lation. 

The  presence  of  the  carbonates  of  lime  is  characteristic  of 
natural  waters  in  limestone  territories  and  is  familiarly  termed 
"temporary  hardness"  or  alkalinity,  the  qualifying  term  "tem- 
porary" being  used  to  distinguish  the  portion  of  the  lime  pre- 
cipitated by  boiling,  the  boiling  having  the  effect  of  releasing 
the  carbonic  acid  as  a  gas.  Natural  waters  which  are  soft  or 
possess  little  or  no  alkalinity  must  first  be  treated  with  lime 
water,  a  solution  of  carbonate  of  soda,  or  some  mineral  base 
of  this  character  before  the  sulphate  of  alumina  solution  is 
introduced. 

The  sulphate  of  lime  and  magnesia  is  a  usual  constituent 
of  natural  waters  and  represents  the  permanent  hardness  of 
water.  In  contrast  with  the  temporary  hardness,*  the  perma- 
nent hardness  is  not  affected  by  boiling. 

Carbonic  acid  as  found  in  natural  waters  is  acceptable,  it  is 
desirable  in  a  drinking-water  and  is  present  in  natural  waters  in 
varying  amounts. 

It  should  be  observed  that  the  use  of  the  sulphate  of  alumina 
introduces  no  new  chemical  compounds  in  solution  in  the  water 
treated;  practically  its  only  effect  is  to  transfer  a  portion  of 
the  mineral  water  in  solution  from  a  state  of  temporary  hard- 
ness to  one  of  permanent  hardness,  but  usually  the  amount  of 
mineral  thus  affected  is  small  in  comparison  with  the  total  amount 
of  hardness  naturally  present  in  the  water  treated.  Of  course 
no  undecomposed  sulphate  of  alumina  should  remain  in  the  water 
after  treatment  and  does  not  remain  when  the  coagulant  is  in- 
telligently used. 

The  hydrate  of  alumina  formed  by  the  chemical  combina- 
tion just  described  is  a  sticky  insoluble  mineral  in  a  finely  divided 
state  when  freshly  formed,  but  gradually  the  small  particles 
unite  as  they  circulate  through  the  water,  collect  the  fine  sedi- 
ment, and  finally  subside  in  small  masses.  This  constitutes  the 
mechanical  part  of  the  process  of  coagulation. 

A  common  practice  is  to  introduce  the  coagulant  solution 
into  the  raw  water  as  it  is  being  delivered  to  the  settling-basin. 
In  cases  where  the  water  is  delivered  to  the  basin  by  pumping, 


140  WATER-SUPPLIES. 

a  small  by-pass  pipe  is  connected,  with  the  main  delivery-pipe 
and  with  a  pressure- tank.  Dry  sulphate 'of  alumina  is  put  into 
the  tank  and  the  top  bolted  on.  Water  from  the  deli  very -pipe 
is  then  turned  into  one  end  of  the  tank,  dissolving  the  sulphate 
of  alumina  as  it  circulates  through  the  tank;  the  solution  pass- 
ing out  at  the  opposite  end  of  the  tank  is  returned  to  the 
deli  very -pipe.  This  method  of  coagulation  is  exceedingly  faulty 
and  crude,  as  it  gives  a  very  irregular  distribution  of  the  coagu- 
lant. Introduced  in  this  manner  the  coagulant  has  apparently 
little  or  no  effect  in  clarifying  very  muddy  water  because  the 
hydrate  of  alumina  is  either  absorbed  by  the  large  amount  of 
organic  matter  usually  present  in  muddy  water  or  becomes 
entangled  with  the  heavy  sediment  as  it  subsides  naturally 
and  goes  to  the  bottom  of  the  basin  without  effect  on  the  fine 
sediment. 

Several  years  ago  the  author  made  a  few  simple  analyses  to 
determine  the  loss  of  coagulant  when  introduced  into  the  raw 
Missouri  River  water,  and  to  determine  a  ratio  of  the  alkalinity 
of  the  water  consumed  in  the  process  of  coagulation  to  the  amount 
of  coagulant  used  in  the  operation.  The  method  employed  in 
these  experiments  was  to  collect  a  sample  of  the  raw  river-water 
as  it  passed  through  the  basin  delivery-pumps  and  to  treat  imme- 
diately one  portion  of  this  sample  with  a  definite  amount  of 
coagulant  solution  of  known  strength,  and  another  equal  por- 
tion of  the  same  sample  after  removing  the  sediment  by  filtra- 
tion with  an  equal  amount  of  the  same  coagulant  solution.  After 
treatment  and  subsidence,  an  aliquot  part  of  each  sample  was 
siphoned  off  and  its  alkalinity  determined  and  compared.  The 
difference  of  the  residual  alkalinity  of  the  two  samples  respec- 
tively was  taken  to  represent  the  equivalent  of  the  coagulant 
absorbing  capacity  of  the  sediment  and  was  reduced  to  grains 
per  gallon  by  dividing  it  by  the  ratio  of  the  alkalinity  consumed 
in  the  treatment  of  the  filtered  sample  to  the  known  amount 
of  coagulant  in  grains  per  gallon  used  in  the  treatment.  The 
results  are  compiled  in  Table  V. 

In  the  experiments  indicated  by  the  results  collated  in  Table  V 
an  effort  was  made  to  keep  a  little  within  the  range  of  the  total 
coagulant  decomposing  capacity  of  the  river-water.  A  proper 


RIVER-WATER  SUPPLY. 


141 


TABLE  V. 


Date. 
1900 

Description 
of  sample. 

Suspended 
matter  in 
river-water, 
parts  per 
million. 

Sulphate  of 
alumina, 
grains  per 
gallon. 

Alkalinity. 

Ratio  of 
alkalinity 
consumed 
to  coagu- 
lant used, 
grains  per 
gallon. 

Coagulant 
absorbed 
by  mud. 
grains  per 
gallon. 

Before 
treat- 
ment. 

After 
treat- 
ment. 

Feb.     5 

3° 

20   5 

230 

53-5 

8.6 

9 

3° 

26.1 

25 

8.7 

"          21 

3° 

23.2 

255 

50 

9.0 

March  2 

3° 

23.2 

230 

27-5 

8.7 

5 

3° 

23.2 

230 

3° 

8.6 

"       7 

Muddy 

740 

"         R 

/  Muddy 

17.4 

175 

43-5 

o 

\  Filtered 

17.4 

35-° 

8.0 

,, 

f  Muddy 

1220 

!5-5 

145 

52-5 

9 

\  Filtered 

i5-5 

25.0 

8-4 

3-3 

44 

/  Muddv 

2315 

ii.  6 

120 

37-5 

I  C 

1  Filtered 

n.  6 

25.0 

7.8 

1.6 

"        12 

/  Muddy 
Filtered 

2520 

ri.6 
ii.  6 

125 

65.0 
35-° 

7.8 

3-8 

,. 

f  Muddy 

ii.  6 

120 

55  o 

3 

1  Filtered 

ii.  6 

35-° 

7-3 

2.7 

tl 

/  Muddy 

200O 

n.  6 

115 

45-° 

14 

\  Filtered 

n.  6 

25 

7-7 

2.6 

4, 

Muddy 

n.  6 

II2.5 

55 

J5 

f  Filtered 

ii.  6 

25 

7-5 

4.0 

„ 

Muddy 

1500 

ii.  6 

Il6.5 

55 

I7 

Filtered 

ii.  6 

3° 

7-5 

3-3 

,, 

Muddy 

1160 

ii.  6 

122.5 

5° 

*9 

\  Filtered 

ii.  6 

37-5 

7-3 

1  •  7 

"        20 

f  Muddy 

ii.  6 

I27-5 

55 

1  Filtered 

ii.  6 

22.5 

9.4 

"        21 

f  Muddy 

2520 

ii.  6 

i36-5 

67-5 

ii.  6 

"             00 

/  Muddv 

ii.  6 

I5° 

75 

2  2 

t  Filtered 

ii.  6 

52.5 

8.4 

2.7 

„ 

/  Muddy 

14-5 

i5° 

52-5 

3 

t  Filtered 

14-5 

40 

7  6 

1.6 

"     24 

f  Muddy 
1  Filtered 

510 

14-5 
14-5 

150 

47-5 
40 

7.6 

i  .0 

44 

f  Muddy 

i75«> 

14-5 

160 

90 

29 

1  Filtered 

14-5 

5° 

7.6 

5-3 

April  28 

J  Muddy 
\  Filtered 

3420 

14-5 
14-5 

125 

75 
22.5 

7-1 

7-4 

"      30 

f  Muddy 
\  Filtered 

14-5 
14-5 

122.5 

50 

7.2 

4-5 

Average 

7-9 

test  showed  that  no  undecomposed  coagulant  remained  in  the 
water  after  each  treatment.  What  difference  there  might  have 
been  in  the  relation  of  the  residual  alkalinities  in  each  set  of 
experiments  had  a  small  amount  of  coagulant  been  used  was 


142 


WATER-SUPPLIES 


not  determined.  The  object  in  view  was  simply  to  confirm  pre- 
vious observations,  made  during  the  actual  working  of  a  large 
settling-basin,  of  the  ineffectiveness  of  introducing  the  coagulant 
directly  into  the  raw  river-water  heavily  burdened  with  sedi- 
ment. The  ratio  of  the  alkalinity  consumed  by  the  coagulant  to 
the  number  of  grains  of  coagulant  used  in  the  treatment  of  the 
water  agrees  fairly  well  in  all  instances  except  that  for  March  2ist, 
which  ratio  is  omitted  in  determining  the  average  ratio  of  7.9. 
It  is  perhaps  practically  correct  to  use  a  ratio  of  8  to  conveniently 
determine  the  capacity,  of  the  Missouri  River  water  at  least,  to 
decompose  sulphate  of  alumina,  and  in  such  computations  as 
follow  this  ratio  has  been  used.  The  ratio  is  only  approximated, 
however,  when  the  amount  of  coagulant  used  in  treating  the 
water  approximates  the  total  coagulant  decomposing  capacity 
of  the  river-water,  as  is  illustrated  by  the  following  table.  The 
water  in  the  subsiding  basin  referred  to  above  on  January  20,  1900, 
having  an  alkalinity  of  210  parts  per  million,  when  treated  with 
different  amounts  of  sulphate  of  alumina  showed  a  variable 
ratio  of  alkalinity  consumed  to  the  amount  of  coagulant  used 
in  the  treatment.  The  results  were  verified  by  analyses  on 
several  succeeding  days. 

TABLE  VI. 


Amount  of  sulphate 

Alkalinity  after 

Ratio  of  alkalinity 

of  alumina  in  grains 

treatment,  parts 

consumed  to 

per  gallon. 

per  million. 

coagulant  used. 

5-8 

146 

II  .  o 

8.7 

122 

IO.O 

ii.  6 

102 

9-3 

14-5 

80 

9.0 

17.4 

63 

8.5 

20.3 

36 

8.1 

23.2 

26 

7-9 

26.1 

IO 

7-7 

The  results  of  the  experiments  recorded  in  Table  V  not  only 
show  the  extreme  wastefulness  of  the  practice  of  introducing 
the  sulphate  of  alumina  into  a  raw  water  heavily  charged  with 
sediment,  but  also  offer  another  reason  for  the  unsatisfactory 
results  to  be  derived  from  the  fill-and-draw  method  of  oper- 
ating a  settling-basin  which  admits  only  of  the  coagulation  of 


RIVER-WATER  SUPPLY. 


the  raw  water  as  it  is  delivered  into  the  basin.  An  attempt 
to  use  an  amount  of  coagulant  in  the  clarification  of  a  very  muddy 
water  which  provides  for  the  losses  above  pointed  out  and  in 
addition  reaches  and  coagulates  the  fine  sediment  which  gives 
persistent  turbidity  to  a  water  after  natural  sedimentation 
entails  a  prohibitive  expense  in  clarifying  water  on  a  large  scale. 

The  most  effective  time  to  introduce  the  coagulant  is  after 
the  water  has  passed  through  a  period  of  natural  sedimentation. 
The  length  of  this  period  varies  with  the  character  rather  than 
the  amount  of  the  sediment  contained  in  the  raw  water  and 
with  the  season  of  the  year  and  should  scarcely  exceed  twenty- 
four  hours  in  length. 

A  coagulant  introduced  into  the  Missouri  River  water  after 
about  83  per  cent  of  the  sediment  had  been  disposed  of  by  about 
twenty-four  hours'  natural  sedimentation  has  proven  very  effec- 
tive. The  amount  of  coagulant  required  for  clarification  is  found 
to  vary  with  the  turbidity  after  the  twenty-four-hour  period  of 
natural  sedimentation,  but  not  necessarily  with  the  amount  of 
sediment  in  the  raw  water. 

In  this  connection  and  as  a  matter  of  illustration  it  may 
be  of  interest  to  tabulate  a  few  analyses  indicative  of  the  character 
of  Missouri  River  water  and  of  the  amount  of  sulphate  of  alumina 
that  is  required  for  clarification. 

The  alkalinity  recorded  in  the  second  column  of  Table  VII  is 
a  measure  of  the  coagulant  decomposing  capacity  of  the  river- 
water  expressed  in  parts  per  million,  and  in  column  4  the 
same  capacity  is  expressed  in  grains  per  million  and  is  found 
by  dividing  the  alkalinity  by  8,  the  ratio  derived  from  Table  VI. 
The  table  embraces  the  period  of  the  least  as  well  as  the  greatest 
alkalinity  of  the  river-water  for  the  interval  of  a  year.  The 
large  surplus  of  alkalinity  beyond  that  required  for  chemical 
union  with  the  sulphate  of  alumina  with  which  the  water  was 
treated  affords  conclusive  proof  that  no  undecomposed  sulphate 
of  alumina  could  have  remained  in  the  clarified  Missouri  River 
water  of  that  year. 

An  absence  of  turbidity  observations  in  the  table  is  notice- 
able and  the  observations  may  accordingly  be  considered  incom- 
plete when  viewed  from  a  scientific  standpoint.  A  few  tur- 


i44 


WATER-  SUPPLIES. 


TABLE  VII. 


Date. 

In  parts  per  million. 

In  grains  per  gallon. 

Alkalinity, 
city  water 
parts  per 
million. 

Alkalinity  of 
river-water. 

Suspended 
matter, 

river-water. 

Coagulant 
decomposing 
capacity, 
river-water. 

Coagulant 
used  in  sub- 
siding-basin. 

Apr.   23,  1899.  . 

535° 

24      "    .. 

3584 

26      "    .  . 

126 

349i 

15-8 

2.18 

120.75 

27      "    •• 

128.6 

2787 

16.1 

1.9 

112.9 

28      "    .  . 

II5-5 

14.4 

1.9 

May     i 

301-3 

2          "       .  . 

120.  7 

5279 

3      "     •• 

131.2 

16  .4 

1-7 

5 

123.4 

4221 

15-4 

i  .  7 

17            .  . 

126 

15-8 

i-55 

19 

126 

2446 

15.8 

1.82 

22          "       .  . 

113.9 

523° 

14.2 

2.76 

1       .   . 

IIO.  2 

13-8 

2.40 

25          "       •  • 

2530 

2.83 

June  10        ;     .  . 

128.6 

8064 

16.1 

0-95 

IIO.  2 

19      '*    .  . 

120.75 

5756 

15.  i 

1.62 

July    n      "     .  . 

120.  7 

3633 

15.  i 

0.95 

IIO.  2 

28      "    .  . 

"5-5 

3418 

14.4 

o  .69 

Aug.     7      "     .. 

107  .6 

13-4 

1.19 

103  .  7 

8    ••-•;.. 

2420 

I  .  OO 

10      "     .  . 

105 

2340 

13.  i 

0.75 

103  .  7 

13      "     •  • 

105 

13  .  i 

1.30 

22           ;       .  . 

120.  7 

1735 

15  .  i 

o.  96 

Oct.    13 

159-3 

19.9 

0.37 

21         "       .  . 

155 

19.4 

o-53 

150 

Nov.     i      "    .  . 

19.7 

0.42 

155 

6      "     .. 

660 

0-44 

8      '•   ... 

160 

20 

0.41 

J57-5 

Dec.   18      "    .  . 

0.23 

170 

21         "      .. 

2IO 

50 

26 

0.22 

I77.S 

30    "  .. 

240 

3° 

O.O 

225 

Jan.      3,1900.. 

O.O 

265 

5      "     .. 

275 

34-4 

O.O 

8      "    .. 

275 

34-4 

0.0 

9 

260 

120 

32.5 

0.23 

ii 

245 

30.6 

O.42 

12         "       .  . 

265 

370 

33-i 

0-45 

*3            •  • 

o  .  55 

25* 

15      "     •• 

2IO 

830 

26.0 

0-75 

235 

16      "     .. 

215 

26  .  9 

o.  76 

227 

18      "    .. 

215 

650 

26  .9 

o.45 

230 

20        "      .  . 

2IO 

IOO 

26  .0 

0.43 

227 

22         "       .  . 

195 

24-4 

o.  50 

2IO 

24         "      .  . 

197 

490 

24.6 

0.50 

2IO 

26         "      .. 

192 

515 

24  o 

o-44 

205 

27           ;       .. 

I9O 

23-8 

0.42 

192 

29           '    ... 

205 

25-6 

0-45 

198 

31         "       ' 

225 

28.0 

0.46 

195 

RIVER-WATER  SUPPLY. 
TABLE  VII  (continued). 


145 


Date. 

In  parts  per  million. 

In  grains  per  gallon. 

Alkalinity, 
city  water, 
parts  per 
million. 

Alkalinity  of 
river-water. 

Suspended 
mater, 
river-water. 

Coagulant 
decomposing 
capacity, 
river-water. 

Coagulant 
used  in  sub- 
siding-basin. 

Feb.     i,  1900.  . 

222.5 

27.8 

o-39 

200 

3 

225 

28.1 

0.21 

217-5 

5 

230 

28.8 

0.0 

22O 

6 

242-5 

3° 

30-3 

0.0 

225 

9 

252.5 

30 

31-6 

240 

12 

255 

3° 

31-9 

250 

14 

255 

3° 

31-9 

252.5 

19 

260 

30 

32.5 

255 

21 

255 

3° 

31.9 

o.o 

257-5 

Mar.     2 

230 

3° 

28.8 

O.  22 

240 

5 

225 

3° 

28.1 

0.24 

232.5 

7 

172.5 

740 

21.6 

0.66 

230 

8 

175 

21.9 

0.74 

2IO 

9 

145 

1220 

18.1 

0.77 

195 

10 

I2O 

2315 

15.0 

1.28 

175 

12 

I25 

2520. 

15-6 

2.34 

155 

13 

120 

15.0 

3.61 

135 

14 

"5 

2000 

14.4 

2.84 

II7-5 

15 

II2.5 

14.1 

2-43 

102  .  5 

16 

I2O 

15.0 

.89 

97-5 

17 

Il6.5 

I5OO 

14.4 

.72 

IOO 

19 

122.5 

1160 

•83 

'°5 

20 

I27.5 

15  .9 

.64 

105 

21 

136-5 

2520 

17.1 

.61 

107-5 

22 

150 

18.8 

.66 

i°7-5 

23 

150 

18.8 

•52 

125 

24 

152 

510 

19.0 

•43 

122.5 

26 

150 

18.8 

.41 

127-5 

29 

160 

175° 

20.  o 

2.24 

142.5 

bidity  observations  were  made  in  the  laboratory,  but  were  dis- 
continued for  the  reason  that  turbidity  observations  of  the  water 
in  the  basin  itself  offered  a  better  guide  for  the  attendant  in 
constant  charge  in  proportioning  the  strength  of  a  day's  coagu- 
lant solution.  An  indication  of  a  progressive  increase  of  tur- 
bidity in  division  3  of  the  settling-basin  was  followed  by  an  in- 
crease of  the  amount  of  coagulant  used  until  the  increase  of 
turbidity  was  checked,  then  the  strength  of  the  coagulant  solution 
was  reduced  accordingly  as  the  decrease  of  turbidity  became 
apparent  in  division  3. 

The  variation  of  turbidity  in  either  division  3  or  4  of  the 
basin  was  very  apparent  to  a  close  observer  of  the  daily  work- 


146  WATER-SUPPLIES. 

ing  of  the  basin  chiefly  in  a  triangular  patch  of  water  extend- 
ing from  the  inner  end  of  the  weir  in  either  division  wall  toward 
the  outer  wall  of  the  basin,  as  indicated  on  Fig.  20.  There  was 
usually  a  rather  sharp  line  of  division  between  the  recently  coagu- 
lated water  and  that  of  the  water  which  had  undergone  partial 
subsidence  after  coagulation.  A  tendency  of  this  line  of  division 
to  move  away  from  the  weir  invariably  indicated  a  gradual 
increase  of  turbidity,  and  if  this  tendency  remained  unchecked 
by  the  use  of  too  small  an  amount  of  coagulant  the  line  of  divi- 
sion would  gradually  encompass  a  larger  and  larger  patch  of 
the  water  and  finally  fade  almost  entirely  in  a  cloud  of  general 
turbidity.  Thus  an  attendant  making  numerous  daily  observa- 
tions of  the  appearance  of  the  water  in  the  several  divisions  and 
having  presented  to  his  eye  the  relative  position  of  the  line  of 
division  between  the  recently  coagulated  water  and  that  par- 
tially subsided  as  the  line  advances  with  the  general  swing  of 
the  water  as  a  body  or  retreats  toward  the  weir,  and  having 
fixed  objects  beneath  the  surface  of  the  water  in  the  clear- water 
basin  by  which  he  could  instinctively  compare  turbidities  of 
succeeding  observations,  could  not  fail  to  detect  slight  variations 
of  turbidity  and  to  act  accordingly  day  by  day  in  proportion- 
ing the  strength  of  the  coagulant  solution.  While  this  fact  and 
these  circumstances  account  for  the  absence  of  a  turbidity 
record  in  Table  VII,  they  are  not  to  be  taken  altogether  as  a 
justification  for  a  neglect  to  make  frequent  laboratory  measure- 
ments of  turbidity  not  only  as  a  matter  of  record  but  also  as  a 
help  in  the  economic  use  of  a  coagulant.  But  however  this  may 
be  it  must  be  acknowledged  that  the  laboratory  observations 
cannot  supplant  those  observations  which  the  attendant  can 
and  must  make  of  the  working  condition  of  a  settling-basin 
from  time  to  time  as  he  moves  along  the  division  walls  and  sees 
the  operation  from  different  points  of  view.  Instinctively  his 
judgment  as  to  the  variations  in  the  management  of  the  basin 
is  largely  governed  rather  by  his  general  observations  of  the 
working  of  the  basin  itself  than  by  laboratory  measurements 
of  turbidity.  The  laboratory  measurements  enable  him  to  record 
the  facts  or  circumstances  which  influence  his  judgment. 

Observations   of  alkalinity  are   the  only  sure  guide   to   the 


RIVER-WATER  SUPPLY. 


safe  use  of  a  coagulant  when  the  raw  water  is  comparatively  soft 
or  of  low  alkalinity  contents  or  during  periods  of  floods,  par- 
ticularly flashy  floods  of  rivers  having  naturally .  hard  water, 
for  then  the  alkalinity  may  run  abnormally  low  at  a  time  when 
there  arises  the  greatest  necessity  for  the  use  of  the  coagulant. 
The  coagulant  decomposing  capacity  of  the  raw  water  should 
always  be  known  to  be  sufficient  for  the  complete  decomposition 
of  the  amount  of  coagulant  required  for  clarification,  and  when 
at  critical  periods  the  alkalinity  runs  too  low  to  completely  neu- 
tralize the  coagulant,  then  the  requisite  amount  of  alkalinity 
must  be  supplied  artificially  by  the  introduction  of  lime-water 
or  a  solution  of  carbonate  of  soda  or  other  alkaline  base. 

TABLE  VIII. — CONSUMPTION   OF  SULPHATE  OF  ALUMINA   IN  THE   KANSAS 

ClTY    SUBSIDING-BASIN    IN    GRAINS    PER    GALLON. 


c  — 
>»c 

&£ 

1899. 

1900. 

Apr. 

May. 

June. 

July. 

Aug. 

Sept. 

Oct. 

Nov. 

Dec. 

Jan. 

Feb. 

Mar. 

Apr. 

i 

•36 

•78 

0.69 

°-93 

I  .  OO 

0.48 

0.46 

0.42 

°-53 

0.00 

0-39 

0.21 

1.67 

2 

.09 

.72 

0.72 

i  .06 

0.69 

o-35 

0.42 

0.42 

o-54 

0.00 

0-37 

0.22 

1.42 

3 

.14 

.70 

0.65 

0.99 

o-75 

°-37 

0.42 

0.44 

0.30 

o.oo 

0.  21 

o.  25 

1.24 

4 

.14 

•56 

°-93 

•54 

o.  69 

0.44 

0.42 

0.44 

0.79 

o.oo 

0  .OC 

0.26 

5 

.14 

.70 

0.83 

•J3 

1.04 

0.36 

0.44 

0.42 

0.98 

o.oo 

o.oc 

0.24 

1.67 

6 

•03 

.78 

°-93 

.00 

1.19 

o-37 

0.44 

0.44 

0.87 

o.oo 

o.oc 

0.  2C 

1.64 

7 

•43 

•71 

0.86 

.02 

1.19 

°-35 

0.42 

0.42 

o,  60 

o.oo 

o.oc 

o.6C 

:-37 

8 

•36 

•7i 

0.89 

.00 

i  .00 

0.38 

0.56 

0.41 

°-43 

o.oo 

0.  OC 

o.7j 

:  .  o 

9 

•63 

•83 

0.96 

.OO 

o-73 

0.42 

0.48 

0.  20 

°-55 

0.23 

0.  OC 

0.77 

i  .64 

10 

.68 

•56 

°-95 

0.99 

°-75 

0.50 

o.45 

0.21 

o.  29 

0.41 

0.00 

i  .28 

2-3 

ii 

•43 

•73 

.70 

°-95 

0.81 

0.42 

0.41 

0.  20 

0.52 

0.42 

o.oc 

1.61 

1.71 

12 

•7i 

.82 

.70 

0.91 

°-93 

0.41 

°-39 

0.24 

0.25 

0.45 

o.oo 

2-34 

1.8 

*3 

.98 

.70 

•55 

0.90 

1.30 

0.41 

°-37 

0.  2O 

0.24 

o-55 

o.oo 

3-6i 

1.86 

14 

•93 

•63 

.72 

o.  96 

I  .  12 

0.42 

0.36 

o  70 

o.  20 

0.49 

o.oc 

2.84 

1.9 

15 

2.28 

•49 

•33 

.06 

0.96 

0.46 

°-39 

0.42 

0.24 

°-75 

o.oo 

2-43 

1.71 

16 

2-37 

•55 

.  12 

.24 

o  96 

0.44 

0.38 

0.77 

O.  22 

0.76 

o.oo 

.89 

!-7 

17 

2.19 

•55 

•43 

•13 

0.69 

0.48 

o-73 

0.41 

o.  25 

0-59 

o.oo 

,72 

18 

.80 

•36 

.  22 

•13 

o  .  96 

0.44 

0-34 

0-44 

0.23 

0-45 

O.  OO 

•93 

19 

.70 

.82 

.62 

.04 

o  89 

0.44 

o-35 

•37 

0.23 

0.44 

o.oo 

•83 

20 

.78 

•73 

•39 

•°5 

r-!3 

0.50 

o-53 

0,47 

0.25 

0-43 

O  .  OO 

.64 

21 

.78 

.96 

•39 

.04 

I  ,  10 

0.42 

°-53 

0.47 

0.  22 

0-54 

O  .  OO 

.61 

22 

.67 

2  76 

•34 

0.78 

o  .  96 

0.42 

o.  56 

o  49 

0.38 

0.50 

0,21 

.66 

23 

•93 

2  .40 

•57 

0.89 

0.82 

0.48 

°-55 

0.23 

0.32 

0.50 

0.25 

•52 

24 

2-34 

3.89 

.01 

i  .04 

0  75 

o.  50 

o.  50 

O  20 

o-39 

0.50 

0'.  21 

•43 

25 

2.17 

2.83 

.41 

0.72 

0.72 

0.46 

0.41 

0,23 

o.45 

0.47 

0  .  22 

•47 

26 

a.iS 

2.69 

•13 

o-75 

0.78 

0.44 

0.41 

0.30 

0.29 

0.44 

o  25 

.41 

27 

I.9C 

2.28 

.16 

I  .00 

2  23 

0.42 

0.41 

o  24 

o.oo 

0.42 

0  .  22 

.46 

28 

I.  pc 

1.63 

.  12 

0.69 

0,85 

0.44 

o-39 

o.  24 

0.00 

0.49 

o.  24 

•36 

29 

I.QC 

J-39 

0.88 

0.72 

0.72 

°-39 

0.46 

o.  46 

0  00 

0.45 

2.24 

30 

i.8£ 

°-93 

1.16 

0.89 

o  46 

0.41 

0.42 

0-51 

0  00 

0.42 

i.5c 

31 

0.72 

o  .  76 

o  .  50 

0.42 

0  .  OC 

0.4e 

1.42 

148 


WATER-SUPPLIES 


The  amount  of  coagulant  used  and  the  distribution  through- 
out the  year  for  the  clarification  of  the  Missouri  River  water  is 
shown  in  Table  VIII. 

Upon  platting  the  few  determinations  of  the  amount  of  sedi- 
ment contained  in  the  Missouri  River  water  after  about  twenty- 
four  hours'  natural  sedimentation  and  the  corresponding  amounts 
of  sulphate  of  alumina  used  in  the  clarification  of  the  river-water 
as  expressed  in  Table  II  and  VII,  the  amounts  of  sulphate  of 
alumina  for  different  degrees  of  turbidity  may  be  roughly 
approximated  as  follows: 

TABLE  IX. 


Suspended  matter  in 
Missouri  River  water  after 
about  24  hours'  natural 
subsidence. 
Parts  per  million. 

Amount  of  sulphate  of 
alumina  required  for 
clarification. 
In  grains  per  gallon. 

SO 

O.O 

IOO 

o-5 

150 

I.O 

2OO 

i-5 

250 

1.9 

300 

2.4 

350 

2.9 

400 

3-4 

450 

3-8 

500 

4-3 

55° 

4.8 

600 

5-3 

The  table  indicates  that  no  coagulant  is  required  when  the 
raw  water  contains  about  50  parts  per  million  of  sediment.  In 
this  condition  the  water  is  acceptable  for  general  use  and  may 
be  even  clearer  than  the  clarified  water  will  be  found  occasion- 
ally during  seasons  of  freshets,  usually  from  March  to  August, 
inclusive,  when  the  turbidity  of  the  clarified  water  has  been 
found  to  range  from  50  to  100  parts  per  million  in  a  settling- 
basin  of  about  four  times  the  amount  of  the  daily  consumption. 
A  basin  of  relatively  less  capacity  requires  the  use  of  relatively 
more  coagulant  than  that  expressed  in  Table  IX. 

In  the  practical  use  of  a  coagulant  it  is  most  desirable  to 
use  a  solution  of  constant  volume  but  of  variable  strength, 
depending  upon  the  turbidity  of  the  water  to  be  treated.  The 
volume  of  the  solution  cannot  be  definitely  stated,  as  it  depends 


RIVER-WATER  SUPPLY.  149 

upon  the  character  of  the  apparatus  used  in  introducing  it  into 
the  water-supply  and  may  vary  somewhat  with  the  character 
of  the  water  to  be  treated. 

The  coagulant  solution  should  be  delivered  under  constant 
head  into  the  water  to  be  treated  by  some  other  method  than 
that  of  direct-pressure  pumping.  It  is  best  to  provide  a  tank 
at  sufficient  elevation  to  give  the  requisite  head  of  discharge 
and  to  deliver  the  solution  into  the  tank  by  means  of  a  pump 
connected  with  the  mixing-tanks.  A  uniform  level  can  be 
maintained  in  the  tank  by  providing  an  overflow-pipe  so  con- 
nected as  to  admit  of  a  return  of  that  portion  of  the  solution 
to  the  mixing-tank  which  is  pumped  in  excess  of  that  required 
for  use.  The  delivery  of  the  solution  should  be  controlled  by 
a  valve  suitably  calibrated  or  a  similar  measuring  device.  A  long 
line  of  iron  pipe  leading  from  the  regulating-tank  to  the  point 
of  distribution  is  especially  objectionable,  as  its  capacity  will 
speedily  become  seriously  impaired  by  heavy  accumulations 
upon  the  interior  walls.  It  is  far  better  to  use  brass  or  lead- 
lined  pipe  for  the  delivery  of  the  coagulant  solution.  The  lead 
is  not  affected  by  the  solution  and  less  readily  clogged  by  deposits. 

The  required  capacity  of  the  coagulant  apparatus  depends 
very  much  upon  the  local  conditions  and  volume  of  the  water 
to  be  treated.  There  should  be  at  least  two  mixing-tanks,  each 
holding  sufficient  solution  for  one  day's  use.  A  tendency  of  the 
solution  to  stratify  in  the  mixing-tanks  should  be  avoided  by 
providing  and  using  an  agitator  to  give  the  solution  occasional 
circulation. 

When  weirs  are  employed  to  pass  the  water  from  one  divi- 
sion of  a  settling-basin  to  another,  the  coagulant  solution  can 
be  very  effectively  distributed  through  pet-cocks  spaced  3  to  4 
feet  apart  in  the  coagulant  pipe  extended  along  the  weir.  The 
solution  discharging  from  the  pet-cocks  enters  the  water  as  it 
flows  in  a  thin  sheet  across  the  weir  and  becomes  thoroughly 
distributed  by  the  circulation  of  the  water,  particularly  if  the 
water  drops  several  inches  from  the  lip  of  the  weir.  Fig.  22 
illustrates  a  method  of  distribution  through  pet-cocks. 

Taken  as  a  whole,  the  process  of  water  clarification  by  the 
combined  process  of  natural  sedimentation  and  coagulation  is  a 


WATER-SUPPLIES. 


decided  improvement  over  that  of  natural  sedimentation  alone, 
if  for  no  other  reason  than  that  there  ensues  a  greater  uniformity 
of  the  general  appearance  of  the  water  throughout  the  year. 
Moreover,  by  an  intelligent  use  of  a  coagulant  a  rapid  transition 
from  a  slightly  turbid  water  to  one  of  intense  turbidity  can  te 
prevented. 

The  methodical  use  of  a  coagulant  to>  promote  and  accelerate 
sedimentation  arose  at  first  simply  because  plain  or  natural  sub- 


Coagulating  Pipe- 


Basin  No.  2 


100'Weir  /*£ Cocks 


From  Puii.p  House 


-X  Cocks 


Basin  No.  3 


|       Kiev. 


. 1 


Elev.  19.5 


sidence  failed  to  give  satisfactory  results.  A  way  was  thus 
opened  of  improving  the  water-supply  without  sacrificing  property 
already  constructed  and  serviceable.  It  was  a  logical  step  in  a 
fuller  development  of  the  usefulness  of  the  settling-basin,  but 
nevertheless  not  a  concluding  step  in  the  art  of  water  clarifi- 
cation. The  process  fails  to  remove  all  the  natural  turbidity 
of  a  river-water  and  leaves  suspended  in  the  partially  clarified 
water  a  portion  of  the  decomposed  coagulant.  Even  a  sample 
of  water  from  the  clear- water  division  of  the  large  settling-basin 
wherein  objects  several  feet  under  water  are  discernible  will 


RIVER-WATER  SUPPLY.  151 

upon  standing  a  few  hours  disclose  small  clots  of  the  hydrate 
of  alumina. 

Convection  currents,  which  are  usual  in  the  spring  and  fall 
of  the  year  in  a  large  settling-basin,  never  fail  to  cause  an  upheaval 
of  the  hydrate  of  alumina.  On  such  occasions,  when  subsidence 
is  sluggish,  the  amount  of  hydrate  appearing  in  the  clear -water 
basin  is  considerably  increased. 

Although  there  is  no  substantial  evidence  that  the  compara- 
tively small  amount  of  the  decomposed  coagulant  which  thus 
reaches  the  water-supply  is  deleterious,  still  it  is  desirable  that 
ah1  of  the  suspended  products  of  coagulation  should  be  removed 
from  the  water  before  reaching  consumers.  This  is  all  the  more 
important  because  the  particles  of  the  coagulant  which  thus 
pass  the  clarification  works  collect  in  the  water-pipes  of  the 
distributing  system  where  the  consumption  is  usually  small  and 
occasionally  receive  a  complete  stirring  up  when  there  is  a  sud- 
den and  abnormal  draft.  On  such  occasions  the  consumers  are 
liable  for  a  brief  period  to  receive  water  quite  heavily  charged 
with  the  hydrate  of  alumina. 

The  author  noticing  this  experimented  a  little  by  drinking 
every  third  day  for  a  period  of  about  a  month  a  small  goblet 
(100  c.c.)  of  clarified  Missouri  River  water  immediately  after 
treatment  with  sulphate  of  alumina  solution  in  proportions  vary- 
ing from  1 1. 6  to  23.2  grains  per  gallon  with  no  noticeable  effect. 
The  only  precaution  observed  was  that  the  dose  of  coagulant 
was  somewhat  less  than  the  coagulant  decomposing  capacity 
of  the  river-water.  The  experiment  was  simply  made  to  for- 
tify a  position  to  meet  any  criticisms  which  might  honestly  arise 
on  the  part  of  any  consumer  who  might  question  the  safety 
of  using  the  coagulant.  The  occasion  never  arose,  however,  to 
advance  the  experimental  argument,  as  the  only  consumer  who 
seriously  objected  to  the  use  of  the  coagulant  filed  his  protest 
in  midwinter  when  the  river  was  ice-bound,  accompanied  by 
the  statement  that  the  "alum  was  so  thick  he  could  taste  it." 
This  objection  was  easily  met  by  showing  him  the  record  that 
no  coagulant  whatever  had  been  used  for  several  weeks  pre- 
ceding this  discovery.  This  mistake  was  attributed  to  the  fact 


152  WATER-SUPPLIES. 

that  the  midwinter  water  of  the  Missouri  River  is  more  than 
double  the  hardness  of  the  summer  flow. 

The  experiment  probably  possesses  little  or  no  scientific  value 
in  the  absence  of  medical  supervision  and  the  brief  period  covered, 
even  though  the  dose  was  concentrated,  but  it  may  be  used  to 
allay  apprehension  founded  solely  on  prejudice,  and  in  this  light 
only  can  it  be  regarded  as  of  value. 

The  remarks  thus  far  regarding  the  use  of  a  coagulant  apply 
specifically  to  sulphate  of  alumina.  But  so  far  as  the  principle 
of  coagulation  is  concerned  the  remarks  will  apply  to  any  coagu- 
lant. It  is  necessary,  however,  to  refer  specifically  to  another 
coagulant,  the  sulphate  of  iron,  which  is  now  used  successfully 
to  a  considerable  extent.  The  coagulating  property  of  iron  in  a 
hydrated  condition  has  long  been  known  and  has  been  frequently 
used  in  the  purification  of  sewage.  Lately  the  cost  of  manu- 
facture has  been  so  reduced  as  a  by-product  of  iron  works  that 
its  market  value  is  considerably  less  than  that  of  sulphate  of 
alumina  and  accordingly  its  sale  is  being  pushed  to  the  front  by 
commercial  interests  as  a  coagulant.  The  action  of  both  coagu- 
lants is  similar  in  the  regard  that  both  require  the  presence  of 
carbonate  of  lime  in  the  water  as  a  base  for  the  chemical  reaction 
which  forms  the  hydrate  acting  as  the  coagulant  to  mechanic- 
ally collect  the  sediment  and  carry  it  to  the  bottom  of  the  settling- 
basin  in  small  masses.  They  differ,  however,  in  the  regard  that 
the  hydrate  of  iron  is  soluble  in  water  containing  free  carbonic 
acid,  while  the  hydrate  of  alumina  is  not  soluble  in  the  acid. 

Ordinarily  the  carbonate  of  lime  in  natural  water  that  is 
available  for  chemical  action  with  the  sulphate  of  iron  is  there 
because  of  the  presence  of  an  excess  of  carbonic  acid  naturally 
present  in  river-water.  Moreover,  one  of  the  results  of  the  chem- 
ical union  of  this  sulphate  of  iron  with  the  natural  carbonate  of 
lime  in  water  is  free  carbonic  acid,  thereby  increasing  the  capac- 
ity of  water  to  dissolve  hydrate  of  iron. 

It  is  not  therefore  practicable  to  use  the  sulphate  of  iron 
solution  alone,  because  after  the  resultant  chemical  reaction  a 
portion  of  the  hydrate  of  iron  is  dissolved  by  the  carbonic  acid 
and  remains  in  solution  in  the  water-supply.  Later,  if  present 
in  considerable  amount,  the  iron  gradually  oxidizes  and  deposits 


RIVER-WATER  SUPPLY.  1 53 

on  the  walls  of  the  water-pipes,  in  the  service-pipes,  or  adheres 
to  the  surface  of  toilet  fixtures  and  utensils  of  domestic  use,  or 
blows  out  through  a  service-pipe  after  a  period  of  disuse  as  a 
rusty  sediment. 

This  difficulty  is  avoided  in  practice  by  treating  the  river- 
water  with  a  solution  of  ordinary  lime-water  to  neutralize  the 
carbonic  acid  sometimes  before  and  sometimes  after  the  solu- 
tion of  sulphate  of  iron  is  introduced.  The  formation  of  hydrate 
of  iron  is  then  complete  because  all  free  carbonic  acid  is  neu- 
tralized by  the  lime-water  and  thereby  the  hydrate  of  iron  is 
enabled  to  act  to  its  fullest  extent  in  coagulating  the  sediment. 
The  practice  of  introducing  lime  into  the  river-water  between 
the  river  intake  and  the  pumps  has  its  objection  inasmuch  as 
particles  of  lime  collect  around  the  valves  of  the  pumps  and 
may  impair  their  operation.  In  one  instance  an  engine  was  tem- 
porarily disabled  by  the  accretions  of  the  undissolved  lime  around 
the  valves  and  in  the  valve-chambers. 

The  presence  of  dissolved  hydrate  of  iron  in  the  water-supply 
may  appear  a  small  matter,  knowing  that  iron  in  water  for  drink- 
ing is  frequently  considered  beneficial,  but  the  tenacity  with 
which  it  attaches  itself  to  toilet  fixtures  and  domestic  utensils 
renders  it  very  much  of  a  nuisance  about  the  household,  so  much 
so  that  when  naturally  present  in  a  water-supply  in  considerable 
amounts  various  communities  have  sought  relief  by  constructing 
purification  works  to  remove  the  iron.  This  objectionable  fea- 
ture in  the  use  of  iron  as  a  coagulant  must  be  regarded  and  pro- 
visions made  to  guard  against  it  in  any  clarification  works  where 
it  is  used. 

The  further  fact  that  the  water  reaches  the  consumer  with 
all  free  carbonic  acid  neutralized  by  the  use  of  lime  is  in  a  measure 
an  objection  which  is  somewhat  offset  by  the  fact  that  the  water 
may  be  somewhat  softened  as  a  direct  result  of  the  lime  treat- 
ment. If  an  overdose  of  lime  is  given  the  water,  the  supply 
becomes  flat  and  insipid  to  the  taste  aside  from  the  caustic  prop- 
erties thus  communicated  to  the  water. 

It  follows  that  the  economical  and  safe  use  of  sulphate  of 
iron  as  a  coagulant  must  be  accompanied  by  a  knowledge  of  the 
character  of  the  water  to  be  treated  obtained  by  making  a  daily 


154  WA7ER-SUP PLIES. 

partial  analysis  of  the  water  in  the  same  manner  and  to  the 
same  degree  that  is  necessary  for  the  proper  use  of  any  other 
coagulant.  The  equipment  of  a  small  laboratory  at  the  puri- 
fication works  for  this  purpose  is  a  matter  of  small  expense,  and 
the  necessary  skill  to  make  the  test  can  soon  be  acquired  by  an 
intelligent  attendant  under  the  guidance  of  an  experienced  ad- 
viser to  prepare  the  chemical  reagents  and  to  direct  the  method 
of  making  the  daily  tests.  This  work  to  be  carried  out  success- 
fully must  become  a  part  of  the  daily  routine  quite  as  much  as 
the  firing  of  a  boiler  or  the  oiling  of  an  engine.  It  should 
become  part  and  parcel  of  an  organized  management  possessing 
sufficient  practical  experience  to  appreciate  the  value  and  abso- 
lute necessity  of  proper  attendance  to  technical  details. 

Both  the  sulphate  of  alumina  and  the  sulphate  of  iron  add 
to  the  permanent  hardness  of  the  water  treated,  but  usually  to  a 
comparatively  small  degree.  Both  are  available  for  coagulating 
purposes,  weight  for  weight,  in  proportion  as  each  contributes 
to  the  formation  of  available  undissolved  hydrate  of  the  respec- 
tive bases  of  aluminum  and  iron.  Consideration  of  the  relative 
cost  is  not  to  be  based  solely  upon  the  market  value  of  either 
salt,  but  should  also  embrace  the  cost  of  the  lime  needed  for  use 
in  connection  with  the  iron  sulphate  and  the  cost  of  maintaining 
the  apparatus  and  applying  the  several  solutions. 

There  is  no  reason  to  suspect  that  the  hydrate  of  iron  will 
entirely  subside  in  passing  through  the  several  divisions  of  the 
settling-basin,  nor  that  it  will  be  sustained  in  a  state  of  suspen- 
sion by  convection  currents  to  any  less  extent  than  is  the  hydrate 
of  alumina  or  the  hydrate  of  iron  in  natural  ground-waters. 
Some  of  the  hydrate  may  be  expected  to  reach  the  distributing  - 
pipes  and  the  consumers.  This  circumstance  need  be  no  more 
objectionable  with  one  coagulant  than  with  another  so  long  as 
iron  is  not  present  in  the  water  used  for  domestic  purposes  to 
an  extent  to  color  articles  of  white  polished  surfaces,  cooking 
utensils,  or  to  discolor  tea,  coffee,  or  articles  of  food  cooked  with  it. 

A  solution  of  sulphate  of  iron  can  be  introduced  with  the 
most  economy  after  the  raw  river-water  has  passed  through  a 
period  of  natural  sedimentation  unless  the  current  of  the  river  is 
so  sluggish  as  to  be  unable  to  carry  in  suspension  anything  but 


RIVER-WATER  SUPPLY.  155 

light  sediment.  The  wide  variation  of  velocity,  of  flow  between 
a  flood  and  a  low-water  stage  of  a  river  marks  a  similar  varia- 
tion in  the  sediment-bearing  capacity  of  the  river,  consequently 
it  is  advisable  to  provide  for  a  period  of  natural  sedimentation 
in  the  construction  of  any  settling-basin,  even  though  it  may  be 
unnecessary  for  operation  the  whole  of  each  year,  or  prepare  to 
use  a  large  amount  of  coagulant  for  brief  periods. 

The  conditions  under  which  the  process  of  coagulation  must 
be  applied  are  so  similar,  regardless  of  the  particular  coagulant 
employed,  that  the  design  of  the  settling-basin  ,and  the  method 
of  operating  it  remain  substantially  the  same.  Even  the  appa- 
ratus for  mixing  and  applying  the  coagulant  may  be  very  simi- 
lar except  that  for  the  use  of  the  sulphate  of  iron  and  its  accom- 
panying solution  of  lime-water  a  somewhat  larger  apparatus  is 
required. 

Experience  has  so  thoroughly  demonstrated  the  need  of  a 
coagulant  in  clarifying  muddy  river-water  that  even  a  much 
more  extended  discussion  of  the  subject  seems  warranted  than 
space  here  admits.  An  endeavor  has  been  made  to  touch  upon 
the  more  important  considerations  in  the  belief  that  they  will 
yet  receive  fuller  development  in  the  practice  of  water  clarifica- 
tion even  with  the  independent  use  of  the  settling-basin. 

As  matters  now  stand  in  the  application  of  the  process  of 
coagulation  to  expedite  sedimentation  the  least  that  can  be 
said  of  the  settling-basin  is  that  it  serves  to  remove  the  grosser 
impurities  of  muddy  water  and  thereby  prepares  the  water  for 
more  complete  purification  by  some  more  refined  process-like 
filtration.  The  most  that  can  be  said  now  of  the  settling-basin 
is  that  when  constructed  of  a  capacity  several  times  the  average 
daily  consumption  of  water  it  can  clarify  a  muddy  water  to  a 
degree  that  renders  it  of  acceptable  appearance  generally,  but 
not  wholly  free  from  sediment  or  from  the  products  of  coagu- 
lation. It  is  essentially  a  clarifying  process  which  thus  far  does 
not  offer  immunity  from  danger  of  disease  germs  which  may 
reach  the  raw  river-water.  The  bacterial  reduction  which  results 
is  purely  an  incident  of  the  removal  of  the  turbidity  and  is  not 
complete.  The  process  of  sedimentation  as  now  practiced  in  its 
most  developed  form  can  be  considered  safe  only  when  applied 


156  WATER-SUPPLIES. 

to  the  clarification  of  a  water  which  when  fairly  well  clarified 
is  altogether  wholesome. 

There  is  a  decided  and  natural  temptation  to  economize  in 
the  use  of  a  coagulant  whenever  there  is  any  apparent  excuse 
for  doing  so,  consequently  we  find  the  coagulant  used  very  unsys- 
tematically.  Such  a  course  is  very  likely  to  follow  frequent 
changes  of  management  of  municipal  water-works  or  to  sug- 
gest itself  to  a  superintendent  of  a  private  company  for  the  pur- 
pose of  increasing  revenue.  Very  few  of  the  small  water- works 
under  either  private  or  municipal  control  seem  to  provide  them- 
selves with  adequate  facilities  for  either  an  intelligent  or  a  sys- 
tematic application  of  a  coagulant  even  when  experience  con- 
cedes the  necessity  for  its  use.  The  attendants  of  these  small 
plants  and  even  of  large  water-works  frequently  get  into  a  rut 
and  follow  the  same  routine  day  after  day  regardless  of  the 
necessity  to  modify  the  manipulation  of  the  clarification  works 
to  meet  the  varying  condition  of  the  raw  river-water.  The  fault 
of  unsystematic  work  in  this  regard  is  not  primarily  that  of  the 
attendant  as  a  rule,  but  rather  that  of  the  management,  which 
may  be  either  too  inexperienced  to  exercise  proper  judgment  or 
too  far  away  to  properly  appreciate  local  conditions  or  to  know 
actual  requirements  from  day  to  day  or  month  to  month,  and 
unwilling  to  delegate  flexible  administrative  powers  to  the  local 
superintendent. 

Winter  Treatment.  —  A  popular  impression  prevails  that 
river-water  like  that  of  the  Missouri  and  similar  rivers  is  most 
impure  during  an  excessively  muddy  condition.  Doubtless  a 
river-water  may  contain  the  greatest  number  of  bacteria  at 
flood  stage,  but  unsightliness  and  the  presence  of  a  large  num- 
ber of  bacteria  should  not  be  confounded  with  dangerous  pollu- 
tion. It  is  not  the  sediment  in  the  water  or  the  actual  number 
of  bacteria  which  should  be  chiefly  regarded  in  estimating  the 
hygienic  quality  of  a  water,  but  rather  the  character  of  the  bac- 
teria found  to  be  present,  particularly  when  of  sewage  origin. 

Most  of  our  large  rivers  receive  sewage  from  many  towns 
and  cities  in  volumes  which  vary  between  comparatively  nar- 
row limits,  while  the  volume  of  discharge  of  a  river  varies  between 
wide  limits.  Consequently  the  low-water  flow  of  the  midwinter 


RIVER-WATER  SUPPLY.  i$7 

season  dilutes  the  sewage  to  a  far  less  degree  than  the  flood  flow 
of  the  spring  and  summer  seasons,  and  accordingly  we  may  natu- 
rally expect  to  detect  evidence  of  dangerous  pollution  more 
readily  during  the  low-water  stage  of  winter.  At  this  season 
of  the  year  the  sluggish  flow  of  the  ice-coated  detrital  river  reduces 
its  sediment-carrying  capacity  to  the  lowest  limit  and  the  water 
becomes  so  clear  that  attendants  unsuspicious  of  its  hygienic 
condition  have  no  hesitation  in  passing  it  into  the  water-mains 
almost  directly  from  the  river  intake.  The  temptation  then  is 
particularly  strong  to  dispense  with  the  course  of  treatment 
which  the  water  usually  receives  in  a  more  turbid  condition  in 
order  to  save  work  and  to  reduce  operating  expenses. 

The  self-purifying  capacity  of  rivers  and  the  high  degree  of 
dilution  which  sewage  frequently  receives  in  mixing  with  the 
water  of  some  large  rivers,  even  at  low-water  stage,  may  render 
the  danger  of  infectious  matter  entering  the  water-supply  inesti- 
mably low.  But  when  the  conditions  for  self-purification  are 
unfavorable  and  sewage  pollution  is  comparatively  recent,  the 
settling-basin  affords  an  inadequate  safeguard  because  little 
bacterial  improvement  of  a  polluted  water  can  be  expected  from 
several  days'  storage  in  an  ice-covered  settling-basin.  The  treat- 
ment of  the  water  with  the  ordinary  coagulant  at  such  a  time 
can  scarcely  add  to  security  by  reason  of  the  absence  of  germi- 
cidal  properties  of  the  ordinary  coagulant  and  of  the  failure  of 
the  coagulant  to  collect  and  to  settle  quickly  in  the  compara- 
tively clear  and  ice-cold  river-water.  But  it  is  sure  that  even 
any  slight  advantage  that  may  then  follow  the  use  of  the  coagu- 
lant will  be  dispensed  with  for  economic  reasons  from  the  moment 
the  river  begins  to  clear  and  the  visual  necessity  for  its  use  is  no 
longer  apparent. 

It  is  clear,  therefore,  if  sewage  pollution  can  be  detected  in 
the  comparatively  clear  water  of  an  ice-bound  river  and  there 
is  available  only  the  settling-basin  in  which  to  remove  the  danger- 
ous or  infectious  matter,  that  the  prompting  motive  of  using 
and  manipulating  the  settling-basin  must  become  one  directed 
to  the  purification  of  the  water  to  meet  a  standard  of  hygienic 
purity  rather  than  one  of  clearness,  and  accordingly  in  some 
localities  midwinter  treatment  must  differ  from  summer  treatment. 


158  WA  TER-SUP  PLIES. 

Germicides. — A  consideration  of  the  use  of  the  settling-basin 
for  the  production  of  a  wholesome  water  from  one  that  is  bac- 
terially  impure  presents  a  new  and  a  possible  range  of  develop- 
ment. The  accomplishment  of  such  a  development  of  the 
settling-basin  must  have  considerable  influence  upon  the 
character  and  cost  of  purification  works.  It  might  result  in 
the  practical  restriction  of  the  biological  filter,  and  possibly  of 
the  mechanical  filter,  to  uses  for  clarification  purposes  and 
would  extend  the  useful  life  of  existing  settling-basins  indefi- 
nitely. Whenever  a  germicide  is  discovered  which  is  harmless 
in  its  effect  upon  the  water-supply,  effective  in  the  destruction 
of  pathogenic  germs,  easy  of  application,  and  comparatively 
inexpensive,  whether  it  be  ozone  or  sulphate  of  copper  or  some 
other  germicide,  it  is  sure  to  receive  an  application  in  sterilizing 
water  which  may  modify  if  not  revolutionize  our  present  methods 
of  water-supply  purification.  Thus  far  the  use  of  sulphate  of 
copper,  suggested  by  Dr.  G.  T.  Moore  as  an  algicide  for  use  in 
destroying  chiefly  the  algae  which  accumulate  so  rapidly  in  storage 
reservoirs,  promises  to  become  a  germicide  of  extended  use  just 
as  soon  as  scientists,  physicians,  and  the  public  can  be  convinced 
that  it  has  no  deleterious  effect  upon  a  drinking-water.  Of 
course  the  use  of  a  germicide  which  destroys  germ  life  through 
some  other  effect  than  by  a  toxic  effect  would  more  quickly 
become  popular,  but  experiment  has  not  progressed  far  enough 
yet  to  finally  determine  the  feasibility  of  the  use  of  a  germicide  of 
the  former  character;  but  we  are  even  now  confronted  with 
the  problem  of  determining  both  the  actual  safety  and  the  safe 
range  of  application  of  a  germicide  of  the  latter  class. 

In  order  to  facilitate  the  use  of  the  sulphate  of  copper  as  a 
germicide  the  manufacturers  of  the  sulphate-of-iron  coagulant 
design  to  combine  the  two  salts  in  the  process  of  manufacture 
so  that  the  coagulant  and  germicide  may  be  introduced  simul- 
taneously in  the  same  solution.  For  certain  practical  reasons 
the  use  of  the  combined  salts  may  be  advantageous,  but  from 
a  technical  point  of  view  the  combination  in  a  single  solution  is 
of  doubtful  utility,  for  the  reason  that  the  conditions  requiring 
a  variation  of  the  coagulant  from  time  to  time  do  not  necessarily 
require  a  similar  variation  of  the  germicide,  while  in  midwinter 


RIVER-WATER  SUPPLY.  159 

the  use  of  the  germicide  alone  may  be  needed  to  sterilize  the 
water.  However  the  manner  of  introducing  a  germicide  into  a 
water  can  be  readily  determined  after  the  practicability  and 
range  of  its  use  shall  have  been  finally  settled.  At  the  present 
time  it  is  too  early  to  predict  to  what  extent  the  use  of  a  germi- 
cide may  influence  the  use  of  the  settling-basin,  but  there  is  now 
substantial  warrant  for  stating  that  the  settling-basin  is  sus- 
ceptible of  still  greater  development  and  that  it  is  destined  to 
become  a  more  highly  regarded  and  scientific  element  in  the 
art  of  water  purification  in  which  germicidal  action  may  become 
an  important  part  of  the  process. 

We  cannot  dispute  the  fact  that  the  successful  use  of  a  coagu- 
lant and  of  a  germicide  with  a  view  of  purifying  or  sterilizing 
water  forces  upon  us  the  necessity  of  providing  skilled  super- 
vision. The  character  of  the  raw  water,  its  influence  upon  chem- 
icals introduced  in  the  process  of  treatment,  the  preparation  of 
the  water  to  receive  the  chemicals  when  necessary,  the  specific 
action  of  the  chemicals,  their  effect  upon  the  water  treated,  and 
the  best  physical  condition  of  the  water  to  promote  germicidal 
action,  together  with  the  practical  difficulties  which  arise  in  treat- 
ing water  in  large  quantities,  are  all  matters  which  can  scarcely 
be  entrusted  to  the  regular  attendant  of  water-works,  but  which 
must  be  understood  and  their  worth  appreciated  by  the  manage- 
ment through  some  guiding  mind  trained  to  investigate  and 
capable  of  reducing  analytical  data  into  some  simple  rule  of 
guidance.  We  cannot  avoid  the  necessity  of  treating  water  for 
hygienic  purposes  so  long  as  our  customs  and  manners  of  life 
serve  to  pollute  directly  and  indiscriminately  the  sources  from 
which  much  of  our  drinking-water  is  derived.  We  must  either 
maintain  our  rivers  in  a  consistent  state  of  purity  or  purify  poi- 
luted  water  taken  from  the  rivers  to  an  extent  conforming  to  a 
high  standard  of  hygienic  purity  or  seek  unpolluted  sources  of 
supply. 

Natural  Coagulation. — The  natural  prejudice  to  the  use  of 
the  ordinary  coagulant  in  treating  the  water-supply  and  the  jus- 
tifiable objections  to  its  careless  use  leads  to  suggesting  a  sub- 
stitute which  is  occasionally  available  and  is  well  worthy  of  a 
trial  application.  A  few  cities  drawing  their  water-supply  from 


160  WATER-SUPPLIES. 

detrital  rivers  have  also  available  a  ground-water  naturally 
impregnated  with  iron  held  in  solution  by  carbonic  acid.  The 
well-known  properties  of  an  iron  water  to  precipitate  the  iron 
as  a  hydrated  oxide  upon  aeration  and  of  hydrate  of  iron  to  act 
as  a  coagulant  suggests  the  expediency  of  cities  so  located  develop- 
ing ground-water  and  mixing  it  after  aeration  with  that  por- 
tion of  the  water-supply  which  is  taken  from  the  river.  Theo- 
retically the  hydrate  of  iron  of  the  well-water  should  in  part  at 
least  coagulate  the  remnant  of  the  sediment  in  the  river-water 
after  exposure  to  a  proper  period  of  natural  sedimentation.  The 
use  of  the  artificial  coagulant  would  then  be  confined  to  an  amount 
needed  only  to  reinforce  the  natural  hydrate-of-iron  coagulant 
if  for  any  reason  it  should  be  found  to  be  deficient  in  quantity. 
Of  course  when  the  amount  of  ground-water  available  is 
sufficient  for  the  entire  supply  of  the  city,  all  that  is  necessary 
is  to  remove  the  iron  from  the  ground-water  by  methods  described 
on  preceding  pages.  But  when  the  amount  of  this  ground-water 
is  insufficient  for  a  full  supply  of  water  the  deficiency  drawn 
from  the  river  and  naturally  settled  may  be  so  thoroughly  coagu- 
lated by  the  iron  in  the  ground-water  as  to  be  thoroughly  puri- 
fied by  the  ordinary  methods  of  sedimentation  and  filtration. 
Where  the  facilities  for  natural  coagulation  exist  a  trial  can  be 
so  readily  and  inexpensively  made  that  it  is  well  worth  the  ex- 
penditure of  time  and  money  in  view  of  the  attractive  induce- 
ments which  the  practical  application  of  the  process  presents. 
There  are  localities  available  for  the  purpose  where  the  iron  of 
the  natural  ground-water  has  been  found  to  vary  from  three- 
quarters  of  a  grain  to  over  four  grains  to  the  gallon,  which 
is  a  range  of  iron  for  coagulating  purposes  suited  to  a  wide 
range  of  turbidity  of  a  naturally  settled  river-water.  Attention 
should  be  given,  of  course,  to  the  respective  mineral  character- 
istics of  the  water  from  the  two  sources  of  supply  with  a  view 
of  maintaining  as  low  a  degree  of  mineralization  of  the  purified 
water  as  possible.  But  this  is  a  matter  to  be  worked  out  in  de- 
tail when  the  application  of  natural  coagulation  is  contemplated. 
The  naturally  coagulated  water  should  be  subjected  to  subse- 
quent sedimentation  or  filtration  as  in  the  case  of  waters  treated 
with  an  artificial  coagulant. 


RfrBR-WATER  SUPPLY.  161 

Filtration. — The  mechanical  action  of  the  process  of  sand 
filtration  is  a  process  of  clogging  whereby  the  voids  of  the  sand 
gradually  become  filled  and  practically  impervious  near  the 
surface  of  the  sand-bed.  In  slow  sand  nitration  the  clogging 
process  is  essentially  confined  to  a  comparatively  thin  layer  of 
sand  at  the  surface  and  to  a  surface  mantel  of  arrested  impuri- 
ties. A  few  inches  of  head  or  water  pressure  is  sufficient  to 
cause  water  to  freely  flow  through  clean  filtering-sand  at  the 
ordinary  rate  of  nitration  of  45  to  135  gallons  per  square  foot 
per  day.  But  as  the  clogging  process  progresses,  the  water- 
pressure  required  to  force  water  through  the  obstructed  passage 
in  the  sand  at  the  stated  rate  gradually  increases  until  it  reaches 
the  practical  limit  of  4  to  6  feet.  Then  the  surface  of  the  filter 
must  be  relieved  of  the  coating  of  impurities  together  with  £  to 
|  of  an  inch  of  the  surface  sand  where  the  clogging  is  the  most 
intense. 

The  rate  of  filtration  of  mechanical  filters  is  much  greater 
than  that  of  slow  sand-filters,  usually  approximating  a  range  of 
2000  to  3000  gallons  per  square  foot  per  day.  This  high  rate 
of  filtration  causes  a  much  deeper  clogging  of  the  filter  sand, 
and  were  it  not  for  the  coagulant,  which  is  always  necessary 
in  mechanical  filtration,  fine  sediment  would  stream  through 
the  pores  of  the  sand  and  enter  the  filter  effluent.  The  coagu- 
lant when  allowed  sufficient  time  to  act  collects  the  particles 
of  sediment  in  masses  and  assists  materially  in  the  operation 
of  clogging  as  the  water  flows  through  the  sand  at  the  stated 
high  rate.  The  penetration  of  clogging  matter  into  the  sand- 
bed  is  necessarily  much  deeper  than  in  that  of  the  slow  sand- 
filter,  and  the  rate  of  clogging  is  directly  proportional  to  the 
rate  of  filtration.  Consequently  in  mechanical  nitration  the 
filtering-sand  cannot  be  cleaned  by  scraping,  but  requires  noth- 
ing less  than  a  complete  stirring  up  and  attrition  of  the  sand, 
grain  against  grain,  to  separate  the  clogging  material  from  the 
sand  and  to  dismember  the  coagulated  masses  sufficiently  to  pass 
off  in  a  flow  of  wash-water  passing  upwards  through  the  sand 
at  a  rate  four  or  five  times  greater  than  the  stated  rate  of  ni- 
tration. All  of  the  sand  in  mechanical  niters  is  washed  at  every 
washing,  but  only  the  dirty  sand  from  slow  sand-filters  is  washed. 


1 6  2  WA  TER-SUP >  PLIES. 

Consequently  if  the  ratio  of  the  superficial  area  of  mechanical 
filters  to  slow  sand-filters  is  i  to  25  for  a  given  quantity  of  water 
filtered  per  day,  then  for  a  depth  of  30  inches  of  sand  the  me- 
chanical filter  will  require  about  twenty  times  more  wash-water 
than  the  slow  sand-filter  for  the  same  grade  and  amount  of 
clogging  material  removed  and  with  equally  perfect  mechanical 
facilities  for  performing  the  washing. 

There  is  a  biological  action  in  slow  sand  filtration  in  some 
conditions  of  raw  river-water  which  serves  by  vital  processes  of 
living  organisms  to  reduce  organic  matter  and  to  extinguish 
bacterial  life.  This  process  is  more  particularly  applicable  to 
waters  of  comparatively  low  sediment  contents  which  are  pol- 
luted by  organic  matter,  particularly  sewage. 

The  efficiency  of  a  filter  depends  in  a  measure  upon  its  clog- 
ging capacity,  and  accordingly  upon  its  mechanical  make-up 
and  the  skill  bestowed  in  its  operation  and  maintenance,  and  is 
measured  by  the  degree  of  clearness  and  hygienic  purity  of  the 
filter  product. 

Thus  filtration  as  now  understood  is  a  refining  process  which 
as  a  part  of  a  clarification  process  removes  suspended  matter 
which  natural  or  plain  subsidence  coupled  with  coagulation  can- 
not remove,  or  which  as  a  purifying  process  removes  not  only 
the  suspended  matter  in  water  but  also  a  very  large  propor- 
tion of  the  bacteria  which  a  raw  water  may  contain.  In  the 
one  instance  the  essential  consideration  is  to  clarify  an  other- 
wise wholesome  water,  while  in  the  other  instance  it  is  to  elimi- 
nate the  living  organisms  with  a  view  of  excluding  from  the  fil- 
tered water  any  disease  germs  that  may  be  in  the  raw  water. 

With  some  waters  the  distinction  between  clarification  and 
purification  is  a  theoretical  rather  than  a  practical  one  from 
the  fact  that  the  refining  process  which  insures  complete  clarifi- 
cation also  accomplishes  so  great  a  reduction  of  bacteria  that 
the  product  of  the  filter  is  considered  safe  and  wholesome.  This 
is  true  of  the  raw  water  of  large  detrital  rivers  containing  a  large 
amount  of  finely  divided  clay  and  possibly  polluting  matter  in  a 
highly  diluted  state. 

There  is  this  distinction,  however,  to  be  made  between  clarify- 
ing filtration  and  purifying  filtration,  namely,  that  the  one  is 


RIVER-WATER  SUPPLY.  163 

governed  largely  by  the  appearance  of  the  filtered  water,  while 
the  other  regards  sanitary  consideration  to  such  a  degree  that 
the  quality  of  the  filtered  water  must  conform  to  a  hygienic 
standard  of  purity,  which  general  experience,  modified  perhaps 
by  local  considerations,  has  found  to  be  a  safe  guide  in  judging 
of  the  wholesomeness  of  a  water. 

Purifying  filters  must  be  operated  continuously,  whereas  the 
operation  of  clarifying  filters  is  sometimes  dispensed  with  when 
the  water  from  the  source  of  supply  is  clear,  as  is  the  case  with 
detrital  rivers  when  ice-bound. 

Notwithstanding  the  distinction  of  theory  which  may  be  made 
between  clarifying  and  purifying  filtration,  this  fact  stands  out 
clear  and  distinct,  namely,  that  filtration  in  any  form  and  for 
any  purpose  should  be  regarded  as  a  refining  process  and  should 
be  so  conducted  that  the  effluent  of  the  filter  meets  the  require- 
ments of  a  standard  of  purity  for  a  wholesome  drinking-water,, 
except  when  applied  merely  to  the  preparation  of  water  for  some 
mechanical  purpose,  when  a  sanitary  standard  of  purity  may  be 
disregarded. 

In  order  that  filtration  may  meet  sanitary  requirements  the 
mechanical  operation  of  filters  must  be  under  perfect  control — 
a  requirement  which  renders  imperative  a  perfect  control  of  the 
condition  of  the  water  admitted  to  the  filter  and  of  the  rate  of 
flow  through  the  filter.  Accordingly  we  must  have  a  standard 
of  hygienic  purity  for  the  filtered  water  and  a  standard,  more 
flexible  perhaps  than  the  former,  to  so  govern  the  condition  of 
the  water  admitted  to  the  filter  that  the  filter  can  continually 
produce  a  water  conforming  with  the  hygienic  standard. 

The  most  available  guide  as  to  what  constitutes  an  acceptable 
standard  of  purity  of  a  filter  effluent  is  the  one  in  use  in  the  Ger- 
man empire  as  follows: 

"Section  i.  In  judging  the  quality  of  a  filtered  surface-water 
attention  is  to  be  paid  to  the  following  points:  (a)  The  opera- 
tion of  the  filter  is  to  be  regarded  as  satisfactory  if  the  number 
of  bacteria  in  the  effluent  does  not  exceed  that  limit  which  experi- 
ment has  shown  to  be  attained  by  good  sand  filtration  at  the 
water-works  in  question.  '  A  satisfactory  effluent  shall  as  a  rule 
not  contain  more  than  about  100  bacteria  per  cubic  centimeter 


1 64  WATER-SUPPLIES. 

when  it  leaves  the  filter,  (b)  The  filtrate  must  be  clear  as  pos- 
sible, and  must  not  be  inferior  in  color,  taste,  temperature,  and 
chemical  character  to  the  water  before  filtration. 

"Section  2.  In  order  to  control  a  water-works  continuously 
in  its  bacteriological  relations,  it  is  advisable  to  examine  the 
effluent  of  each  filter  daily  where  the  conditions  permit.  Such 
a  daily  examination  is  particularly  important:  (a)  after  the  con- 
struction of  a  new  filter  until  it  assumes  its  regular  working  con- 
ditions; (b)  whenever  a  filter  is  put  in  operation  after  cleaning 
and  for  at  least  two  days  after  that  time,  until  the  effluent  has 
a  satisfactory  character;  (c)  after  the  filtration  head  becomes 
more  than  two-thirds  of  the  maximum  for  the  works  in  ques- 
tion; (d)  when  the  filtration  head  suddenly  decreases;  (e)  during 
all  unusual  conditions,  especially  at  times  of  high  water. 

"Section  3.  In  order  to  be  able  to  conduct  bacteriological 
investigations  according  to  Section  i  (a)  the  effluent  of  each 
filter  must  be  accesseble,  that  samples  may  be  taken  at  any 
desired  time. 

"Section  4.  In  order  to  assume  a  uniform  system  of  bac- 
teriological investigations  the  method  given  below  is  recom- 
mended for  general  use. 

"Section  5.  The  persons  intrusted  with  the  conduct  of  the 
bacteriological  investigations  must  furnish  proof  that  they  possess 
the  qualifications  necessary  for  the  work.  They  should  belong 
to  the  official  operating  staff  itself  whenever  possible. 

"Section  6.  If  a  filter  furnishes  water  which  does  not  meet 
the  hygienic  requirements,  it  is  to  be  cut  out  of  service,  pro- 
vided the  cause  of  the  deficient  character  has  not  already  been 
removed  during  the  course  of  the  bacteriological  investigations. 
In  case  a  filter  furnishes  an  unsatisfactory  effluent  oftener  than 
occasionally,  it  is  to  be  placed  out  of  service  and  the  defects 
sought  out  and  remedied. 

"  Section  7.  In  order  to  be  able  to  waste  poor  water  which 
does  not  meet  the  requirements  each  filter  must  be  arranged 
so  that  it  can  be  cut  off  from  the  filtered  water-mains  and  the 
effluent  allowed  to  flow  away.  This  waste  is  to  take  place  regu- 
larly, so  far  as  the  details  of  management  permit,  (a)  immedi- 
ately after  the  complete  cleaning  of  the  filter,  and  (b)  after  com- 


RIVER-WATER  SUPPLY.  165 

pletely  renewing  the  bed  .of  sand.  The  superintendent  in  charge 
must  determine,  from  his  experience  with  the  bacteriological 
investigations,  whether  a  waste  of  effluent  is  necessary  in  each 
individual  case  after  the  completion  of  this  cleaning  or  renewal 
and  the  length  of  time  that  must  elapse  before  the  effluent  attains 
the  required  degree  of  purity. 

"  Section  8.  It  is  necessary  for  satisfactory  sand  nitration 
for  the  surface  of  the  niters  to  have  ample  dimensions  and 
provide  sufficient  reserve  to  assure  the  velocity  of  nitration 
suitable  for  the  local  conditions  and  the  character  of  the  raw 
water. 

"Section  9.  Each  filter-bed  must  be  controllable  as  respects 
quantity  of  effluent,  excess  pressure,  and  character  of  effluent. 
It  must  also  be  arranged  so  that  it  can  be  completely  emptied, 
and  also  be  filled  from  below  with  filtered  water  after  each  clean- 
ing. 

"Section  10.  The  speed  of  filtration  in  each  filter-bed  must 
be  capable  of  adaptation  to  the  most  favorable  conditions  for 
filtration  at  any  time,  and  be  as  regular  and  free  from  sudden 
fluctuations  or  interruptions  as  possible.  To  this  end  the  usual 
fluctuations  caused  by  the  varying  demand  for  water  during 
different  portions  of  the  day  are  to  be  equalized  as  far  as  pos- 
sible by  reservoirs. 

"Section  n.  The  filter-beds  are  to  be  so  arranged  that  their 
operation  will  not  be  influenced  by  varying  levels  of  the  water 
surface  in  the  clear-water  reservoir. 

"Section  12.  The  excess  filtration  head  must  never  be  so 
great  that  breakage  of  the  filtering-top  layer  can  occur.  The 
limit  to  which  the  excess  pressure  may  rise  without  influencing 
the  effluent  is  to  be  determined  for  each  plant  by  bacteriological 
investigations. 

"  Section  13.  The  filters  shall  be  constructed  in  such  a  manner 
that  every  portion  of  the  surface  of  each  bed  shall  work  as  uni- 
formly as  possible. 

"  Section  14.  The  walls  and  bottom  of  a  filter  are  to  be  water- 
tight, and  particularly  must  there  be  no  danger  of  an  imme- 
diate connection  or  passage  through  which  raw  water  may  pass 
from  the  filter  into  the  filtered-water  main.  For  this  purpose 


1 66  WATER-SUPPLIES. 

special  attention  is  to  be  paid  to  a  water-tight  construction  and 
maintenance  of  the  air-shafts  of  the  filtered-water  mains. 

"Section  15.  The  thickness  of  the  bed  of  sand  shall  be  at 
least  so  great  that  the  cleaning  will  never  reduce  it  to  less  than 
30  centimeters  (12  inches)  where  the  conditions  permit.  Never- 
theless it  is  recommended  that  this  minimum  limit  be  raised 
to  40  centimeters  (16  inches)  where  the  conditions  permit. 

"Section  16.  It  is  desired  that  annual  reports  be  made  from 
all  the  sand-filtration  works  in  the  German  empire  to  the  Imperial 
Board  of  Health,  giving  the  results  of  operation,  and  particularly 
the  bacteriological  character  of  the  water  before  and  after  ni- 
tration." 

Experience  or  local  requirements  may  suggest  modifications 
of  the  quoted  regulation.  But  in  whatever  degree  modifica- 
tion may  be  found  advisable,  conformity  thereto  requires  a 
methodical  uniformity  of  the  methods  of  operating  filters  and 
perfect  control  of  the  facilities  for  preparing  the  raw  water  for 
the  filters. 

It  is  well  known  to  those  who  have  observed  the  operation 
of  filters  and  who  have  studied  the  results  of  filtration  that  a 
uniform  rate  of  flow  through  the  filter  and  sufficiently  long  expo- 
sure of  the  water  to  the  purifying  agency  is  necessary  to  insure 
that  degree  of  purification  which  will  meet  the  requirements 
of  a  proper  standard  of  purity.  But  a  uniformity  of  flow  through 
the  filter  cannot  be  preserved  if  too  wide  a  range  of  the  amount 
of  sediment  in  the  water  supplied  to  the  filter  is  allowed,  for 
then  the  rate  of  clogging  becomes  variable,  requiring  a  propor- 
tionately irregular  fluctuation  of  the  filtering  water-pressure 
even  beyond  permissible  limits,  and  resulting  in  an  irregularly 
turbid-water  delivery  of  the  filter.  Under  these  circumstances 
the  bacterial  efficiency  of  the  filter  is  also  reduced  because  high 
bacterial  variation  invariably  accompanies  a  sudden  or  excessive 
variation  of  turbidity  of  the  filtered  water.  In  other  words,  the 
filtering-machine  is  then  overworked,  overclogged,  and  disor- 
ganized, and  accordingly  fails  to  respond  to  the  requirements  of 
the  situation  to  deliver  an  acceptable  product. 

The  neglect  to  provide  the  facilities  which  insure  a  uniformity 
of  the  physical  condition  of  the  water  entering  a  filter  and  of  the 


*  RIVER-WATER  SUPPLY.  167 

working  regime  of  the  filter  itself  accounts  for  numerous  failures 
of  mechanical  filters  and  for  the  occasional  disappointing  result 
of  slow  sand-filters  whenever  the  physical  and  bacterial  con- 
dition of  the  raw  river-water  is  made  to  vary  through  natural 
causes.  Practice  in  this  regard  must  be  modified  in  this  country 
and  far  more  attention  must  be  given  to  the  preparation  of  the 
raw  water  for  filtration  if  the  results  are  to  conform  reasonably 
well  to  a  standard  of  hygienic  purity  of  the  order  quoted  from 
the  German. 

So  long  as  the  theory  prevails  that  certain  forms  of  bacterial 
life  in  water  are  to  be  feared  rather  than  the  dissolved  impuri- 
ties, and  so  long  as  the  science  of  biology,  or  rather  the  line  of 
practice  based  upon  the  developments  of  this  science,  is  unable 
to  discriminate  with  precision  between  the  harmless  and  danger- 
ous bacteria  and  to  identify  individual  types  independently, 
we  are  bound  to  consider  the  complete  removal  of  bacteria 
from  the  water-supply,  or  if  complete  removal  be  found  imprac- 
ticable, then  to  eliminate  the  probability  and  to  minimize  the 
possibility  of  the  presence  of  the  more  dangerous  forms  of  bac- 
teria. 

At  the  present  time  this  principle  or  rule  of  practice  appears 
fundamental,  and  if  fundamental,  then  the  practical  standard 
of  purity  should  be  based  upon  a  limited  number  of  bacteria 
remaining  in  the  filtered  water  rather  than  upon  a  percentage 
of  the  number  in  the  raw  water  removed  by  filtration.  But 
why  not  sterilize  the  water  and  be  done  with  it  and  make  this 
the  universal  standard  of  purity?  To  this  puestion  an  answer 
is  that  it  is  useless  to  plunge  into  a  labyrinth  of  practical  difficul- 
ties which  surely  must  involve  one  who  attempts  to  obtain  a 
sterile  water  from  an  artificial  filter,  for  the  filter  has  practical 
limitations  depending  upon  its  design  and  construction,  upon  the 
method  of  operation  and  upon  the  condition  of  the  water  ad- 
mitted to  the  filter.  It  is  perfectly  plain,  to  use  an  extreme 
case,  if  the  water  could  be  sterilized  before  entering  the  filter  that 
the  work  of  the  filter  would  be  confined  to  that  of  clarification, 
and  that  structural  and  operating  details  would  then  be  of  a 
character  which  would  prevent  the  filter  becoming  a  breeding- 
place  for  bacteria.  While  we  can  scarcely  hope  for  such  perfection 


1 68  WATER-SUPPLIES. 

in  the  works  intended  for  the  preparation  of  water  for  niters  as  to 
produce  the  result  just  outlined,  still  the  nearer  that  sort  of  prep- 
aration is  approached  the  more  readily  can  a  high  standard  of 
purification  be  attained.  It  is  the  pivotal  point  to-day  in  the  proc- 
ess of  water  purification.  If  energy  is  concentrated  upon  the  per- 
fection of  mechanical  devices  in  and  about  filters,  relying  purely 
upon  filtration  as  modified  and  influenced  by  the  mechanical 
devices  to  produce  results,  the  longer  will  the  attainment  of  a 
high  standard  of  purity  of  filtered  water  be  postponed.  On 
the  other  hand,  if  energy  is  devoted  to  the  perfection  of  works 
for  the  preparation  of  water  for  the  filters  of  a  quality  which 
renders  high-grade  filtration  not  only  possible  but  positive,  the 
sooner  may  we  expect  to  see  rapid  advances  made  towards  the 
adoption  of  a  universal  high-grade  standard  of  hygienic  purity 
of  the  water-supply.  Accordingly  there  appears  no  good  reason 
for  much  flexibility  in  the  quoted  standard  of  hygienic  purity 
in  order  to  meet  varying  natural  conditions  of  the  sources  of 
water-supply  as  they  change  geographically,  because  the  vari- 
able conditions  call  for  a  modification  rather  of  the  preliminary 
treatment  of  the  water  and  accordingly  a  modification  of  the 
structures  by  means  of  which  the  preliminary  work  is  accom- 
plished. Whatever  elasticity  there  may  be  in  methods  and  means 
of  water  purification  should  be  largely  confined  to  the  prelim- 
inary preparation  of  water  before  it  reaches  the  filter.  And 
the  extent  to  which  the  physical  condition  of  the  raw  water  must 
be  improved  before  it  is  admitted  to  the  filter  is  largely  a  matter 
for  local  consideration  and  must  be  settled  independently  in 
individual  instances. 

The  city  of  Bremen,  Germany,  takes  its  supply  of  water  from 
the  river  Weser  and  meets  the  requirements  of  the  German 
standard  of  purity  of  filtered  water  by  resorting  to  double  filtra- 
tion. Eugene  Goetze,  Esq.,  chief  engineer  of  the  water-works 
of  that  city,  in  a  paper  presented  to  the  American  Society  of 
Civil  Engineers  September  4,  1903,  concisely  outlines  the  phys- 
ical condition  of  the  river-water  and  the  results  of  filtration  in 
these  words:  "The  number  of  bacteria  in  the  raw  water  of  the 
Weser,  which  normally  is  about  1000  to  2000  per  cubic  centi- 
meter but  often  is  only  a  few  hundred,  increases  at  high  water, 


RIVER-WATER  SUPPLY.  169 

such  as  occurs  regularly  once  or  twice  in  the  fall  and  once  or 
twice  in  the  spring,  to  100,000  per  cubic  centimeter.  ...  In 
Bremen  the  water  formerly  filtered  by  single  filtration  contained 
during  every  flood  1000  to  3000  bacteria,  instead  of  the  permis- 
sible 100  and  was  quite  turbid  besides.  Since  the  introduction 
of  double  nitration  the  city  receives  also,  during  floods,  a  clean 
filtrate  with  no  more  than  about  100  bacteria  per  cubic  centi- 
meter." 

The  raw  water  from  the  river  Weser  is  admitted  directly  to  the 
Bremen  filters,  and  the  requirements  of  the  German  standard  of 
purity  are  met  by  single  filtration  under  ordinary  conditions  of  the 
river-water  and  by  double  filtration  upon  those  occasions  when 
the  river-water  is  abnormally  turbid,  which  may  be  inferred  is  for 
a  comparatively  brief  period  each  year. 

The  Bremen  filters  are  the  biological  or  slow  sand  type,  which 
are  cleaned  by  scraping.  In  this  connection  Mr.  Goetze  states: 
"The  filtering  periods  between  consecutive  cleanings  range  from 
a  minimum  at  a  time  of  high  water  of  about  7  days  to  a  maximum 
of  about  120  days,  the  average  being  30  to  35  days." 

It  is  gathered  further  from  Mr.  Goetze's  tabulations  of  results 
that  the  abnormal  turbidity  of  the  raw  Weser  water  scarcely 
reaches  200  parts  per  million,  and  that  single  filtration  suffices 
for  a  turbidity  of  the  raw  water  of  about  20  to  30  parts  per  mil- 
lion or  less. 

In  the  matter  of  slight  turbidity,  or  rather  of  a  narrow  range 
of  turbidity,  the  few  rivers  of  the  United  States  which  are  com- 
parable with  the  Weser  are  principally  those  of  the  New  England 
and  neighboring  States.  Many  rivers  of  the  Middle  West  and  of 
the  South  are  muddy,  carrying  a  sediment  in  excessive  amounts 
during  the  greater  portion  of  each  year.  While  double  filtration 
may  answer  the  requirements  of  a  proper  standard  of  purity  with 
waters  similar  to  that  of  the  Hudson  and  Merrimac  rivers,  it 
could  not  be  used  to  satisfactorily  purify  or  clarify  the  waters 
from  most  of  the  rivers  of  the  Middle  West.  The  burden  of  sedi- 
ment is  far  too  great. 

The  following  table  taken  from  the  report  of  the  Water-supply 
Commission  of  St.  Louis,  1902,  shows  approximately  the  average 
amount  of  sediment  in  river-water  at  several  localities. 


1 70  WA  TER-SUPPL1ES. 

Parts  per  million. 

Merrimac  River,  Lawrence 10 

Hudson  River,  Albany 15 

Allegheny  River,  Pittsburg 50 

Potomac  River,  Washington 80 

Ohio  River,  Cincinnati , 230 

Ohio  River,  Louisville 350 

Mississippi  River,  New  Orleans 650 

Mississippi  River,  water-works  intake,  St.  Louis .  .  1200 

Mississippi  River,  Missouri  side,  St.  Louis 1500 

Elsewhere  in  this  chapter  is  shown  the  large  amount  of  sedi- 
ment carried  by  the  Missouri  River  near  Kansas  City,  ranging  from 
500  to  over  6000  parts  per  million,  averaging  nearly  3000  parts 
per  million  during  the  months  of  open  river.  When  the  river 
is  ice-bound  the  river-water  is  turbid  only,  the  turbidity  ranging 
from  30  to  50  parts  per  million,  or  possibly  less  during  protracted 
freezing  weather. 

It  is  obvious  that  rivers  like  the  Missouri,  Mississippi,  and  Ohio, 
having  a  wide  range  of  sediment  capacity  marked  by  sudden 
variations,  cannot  receive  satisfactory  preparation  for  filtration  in 
preliminary  niters,  for  the  burden  of  sediment  is  so  great  that 
it  can  be  disposed  of  successfully  by  the  less  expensive  method  of 
sedimentation. 

The  settling-basin  is  usually  the  place  where  the  roughening 
work  of  preparation  can  be  accomplished  and  where  the  water  can 
be  prepared  thoroughly  for  the  refining  work  of  the  filter  to  a 
degree  that  will  meet  the  requirements  of  a  standard  of  hygienic 
purity  of  the  filter  effluent.  But  there  must  necessarily  be  some 
fixed  limit  to  the  turbidity  of  the  effluent  from  the  settling-basins, 
in  order  that  the  filters  may  satisfactorily  perform  the  after-work. 
What  should  be  this  limit  of  turbidity  ? 

George  W.  Fuller,  in  his  report  of  the  Cincinnati  experiments 
relating  to  the  "English"  (slow  sand)  system  of  filtering,  states: 
"  Upon  taking  into  consideration  all  of  the  evidence  at  the  close 
of  the  work,  it  is  finally  concluded  that  the  maximum  permissible 
amount  of  clay  in  the  Ohio  River  water  applied  day  after  day  to 
English  filters  under  local  conditions  ranges  from  about  30  to  70 


RIVER-WATER  SUPPLY.  i?1 

and  averages  between  40  to  50  parts  per  million."  "  To  make  use 
successfully  at  all  times  of  English  filters  it  would  be  necessary 
at  times  of  freshets  to  give  the  Ohio  River  at  Cincinnati  further 
preparatory  treatment  than  is  afforded  by  three  days  of  plain 
subsidence." 

Robert  Spurr  Weston,  in  his  report  on  the  New  Orleans  experi- 
ments, states  with  regard  to  English  niters  that,  "  barring  compli- 
cations from  algae  growths  which  would  tend  to  reduce  the  yield 
of  the  filter  between  scrapings,  a  silica  turbidity  of  35  parts  per 
million  (about  20  parts  of  suspended  matter)  would,  on  an  average, 
permit  according  to  available  data  regarding  local  conditions^ 
a  yield  of  about  65  million  gallons  of  filtered  water  per  acre,  or  a 
period  of  service  between  scrapings  of  about  13  days,  when  a  head 
of  four  feet  is  used.  ...  If  the  water  applied  to  the  filter  should 
be  as  low  in  turbidity  as  20  parts  per  million,  silica  standard,  the 
yield  of  filtered  water  between  cleanings  would  be  considerably 
more,  and  the  penetration  of  the  clay  into  the  sand  layer  would 
very  likely  be  a  little  less.  On  an  average,  and  in  the  ab- 
sence of  algae  growths,  the  data  indicate  that  with  such  an  applied 
water  a  yield  of  100  million  gallons  per  acre  between  scrapings, 
equivalent  to  a  period  of  service  of  20  days,  could  be  obtained, 
and  that  the  depth  of  sand  removed  by  scrapings  would  be  less 
than  one  inch.  It  seems  doubtful  whether,  as  a  rule,  it  would  be 
economical  under  local  conditions  to  apply  sufficient  coagulant  to 
reduce  the  silica  turbidity  of  the  filter  influent  to  20  parts  per 
million  (about  12  parts  of  suspended  matter),  although  better  re- 
sults would  probably  accompany  the  lower  turbidity." 

Mr.  Weston,  in  summing  up  the  results  of  experiments  with 
mechanical  filters  at  New  Orleans  in  purifying  the  Mississippi 
River  water,  gives  the  table  reprinted  on  page  172. 

With  reference  to  this  table  Mr.  Weston  says:  "  It  is  believed 
from  the  above  that  it  is  not  economical  to  apply  a  coagulant 
to  reduce  the  turbidity  of  the  water  to  below  50  parts  per  million 
(30  parts  of  suspended  matter  per  million).  It  is  also  believed 
that  considerable  saving  is  affected  by  reducing  the  turbidity  to 
below  75  parts  per  million  (45  parts  of  suspended  matter  per 
million);  but  it  is  an  open  question  what  should  be  the  proper 
turbidity  between  these  general  limits  to  which  to  reduce  the 


I72 


WATER-SUPPLIES. 


subsided  water  in  order  to  effect  the  most  satisfactory  and  eco- 
nomical filtration." 

TABLE  X. — APPROXIMATE  RELATION  BETWEEN  TURBIDITY  OF  FILTER 
INFLUENT,  PERCENTAGE  AND  COST  OF  WASH-WATER,  AND  YIELD  op 
THE  FILTER  BETWEEN  THE  WASHINGS. 


Influent. 

Wash-water. 

Silica, 
turbidity. 
Parts  per 
million. 

Suspended 
matter. 
Parts  per 
million. 

Percentage. 

Cost 
per  million 
gallons. 

Period 
of  service. 
Hours. 

Yield, 
million  gallons 
per  acre  per  day 

25 

15 

1-5 

$0.27 

29 

ISO 

50 

3° 

2  .O 

0.36 

21 

no 

75 

45 

3-o 

o-54 

13 

70 

IOO 

60 

4.0 

0.72 

10 

50 

150 

90 

6.5 

i-i? 

6 

30 

Other  statements  of  the  general  tenor  may  be  given,  but  all 
point  to  what  must  be  recognized  as  a  fact  that  within  proper 
limits  the  lower  the  turbidity  of  the  water  admitted  to  a  filter 
the  higher  and  easier  becomes  the  permissible  degree  of  purifi- 
cation of  the  water  in  passing  through  the  filter. 

Particular  attention  is  called  to  the  amount  of  wash-water 
that  is  required.  It  is  seen  in  the  preceding  table  that  6J  per 
cent  of  the  total  product  of  the  filter  is  required  for  washing 
purposes  when  the  raw  water  contains  90  parts  per  million  of 
suspended  matter;  it  is  also  known  from  general  practice  that 
the  percentage  of  wash-water  increases  rapidly  as  the  amount 
of  suspended  matter  in  the  raw  water  increases,  and  soon  reaches 
a  point  where  the  large  percentage  of  wash-water  coupled  with 
an  excessive  use  of  a  coagulant  renders  the  expense  prohibitive. 
With  high  sediment  contents  of  the  raw  water,  moreover,  filters 
cannot  be  maintained  in  an  efficient  working  condition. 

The  practical  limitations  to  the  reduction  of  turbidity  may 
approximate  50  parts  per  million  for  water  of  silt -bearing  rivers, 
during  the  unfavorable  seasons  of  the  year,  by  the  skillful  use  of  a 
coagulant  after  the  water  has  experienced  a  period  of  natural 
subsidence  of  12  to  24  hours.  A  greater  reduction  of  turbidity  may 
be  readily  effected  during  more  favorable  seasons  of  the  year 
with  the  use  of  a  less  amount  of  coagulant  skillfully  applied  to 


RIVER-WATER  SUPPLY.  173 

an  amount  approximating  20  parts  per  million,  also  after  a  similar 
period  of  plain  subsidence.  But  in  any  event  the  reduction  of 
turbidity  to  a  proper  degree  to  admit  of  successful  filtration  of 
the  water  of  silt-bearing  rivers  must  be  obtained  with  the  aid 
of  a  coagulant  used  approximately  in  the  amounts  indicated  else- 
where in  this  chapter. 

Two  serious  difficulties  arise  in  connection  with  the  operation 
of  a  settling-basin  in  a  skillful  manner,  one  is  the  objection  to  the 
expense  entailed  in  the  use  of  a  coagulant  in  the  skillful  manner 
and  in  the  amounts  required  for  the  reduction  of  turbidity  to  the 
extent  indicated  above  and  the  other  is  the  popular  objection  to 
the  use  of  a  coagulant  in  large  amounts.  Either  objection  can  be 
met  only  by  insisting  on  the  one  hand  upon  a  proper  standard 
of  purity  of  the  filtered  water  and  on  the  other  hand  by  a  more 
general  familiarity  with  the  process  of  coagulation  and  the 
necessity  for  the  use  of  the  coagulant. 

The  capacity  of  the  basin  that  is  required  for  coagulation  and 
subsidence  after  coagulation  and  for  temporary  unserviceability 
during  the  cleaning  or  washing  process  amounts  to  24  to  36  hours, 
which  capacity  added  to  the  12  to  24  hours'  capacity  required  for 
plain  subsidence  makes  the  total  capacity  of  a  basin  required  for 
successful  operation  of  36  to  60  hours'  supply,  without  considering 
the  capacity  of  the  needed  clear-water  storage-reservoir.  The 
velocity  of  flow  in  some  rivers  is  so  low  for  a  considerable  portion 
of  each  year  that  the  river-prism  becomes  a  subsiding-basin. 
Then  the  raw  river-water  may  be  given  a  treatment  with  the 
coagulant  as  taken  from  the  river  and  afterwards  allowed  a  few 
hours'  rest  in  a  basin  before  going  to  the  filters  to  allow  the 
coagulant  time  to  collect  in  masses  large  enough  to  be  retained 
by  the  filter-sand.  The  current  of  other  rivers  is  so  rapid  the  year 
through,  except  when  ice-bound,  as  to  require  basins  of  the  capacity 
stated  in  the  preceding  part  of  this  paragraph.  Accordingly 
there  is  room  for  a  considerable  latitude  of  judgment  in  fixing 
upon  the  capacity  of  subsiding-basins  which  will  meet  the  general 
requirements  of  local  conditions  most  economically. 

The  amount  of  clear-water  storage  at  the  purification  works  need 
not  exceed  that  which  will  safely  obviate  the  necessity  of  forcing 
the  settling-basin  beyond  its  proper  turbidity-reducing  capacity. 


174 


WATER-SUPPLIES. 


Fig.  23  shows  a  plan  of  a  water-purification  works  (not  con- 
structed) designed  to  purify  water  taken  from  the  Missouri  River 
at  Fort  Leaven  worth,  and  serves  to  illustrate  a  purification 
works  combining  natural  subsidence,  coagulation,  and  mechanical 
filtration,  and  also  a  convenient  arrangement  of  valves  for  manip- 
ulating the  basin. 


to  River 


FIG.  23. — Plan  of  Settling-basin,  Mechanical  Filter,  and  Covered 
Clear- water  Basin. 

The  purification  plant  is  designed  for  the  delivery  of  at  least 
one  million  gallons  per  day  of  wholesome  water. 

The  settling-basin  is  in  three  divisions,  one  division  of  a  capa- 
city of  1,227,600  gallons,  the  second  of  852,000  gallons,  and  the 
third  of  438,000  gallons  capacity.  The  mechanical  filters  are 
each  17  feet  long  and  10  feet  wide  and  of  an  estimated  normal 
filtering  capacity  of  about  400,000  gallons  each  per  24  hours  at 


RIVER-WATER  SUPPLY. 


175 


a  rate  of  about  100  million  gallons  per  day  per  acre,  or  a  little 
over  1.6  gallons  per  square  foot  per  minute. 

Sectional  elevations  of    the  purification  works  are  shown  in 


"0 


r 


IT: 


• 

Fig.  24,  and  a  general  plan  of  the  pipe  system,  valves,  and  gate- 
chamber  on  Fig.  25. 

The  12-inch  raw-water  influent-pipe  divides  at  the  gate-chamber 


i76 


WATER-SUPPLIES. 


wall  into  two  branches,  one  leading  into  division  i,  and  the  other 
into  division  2  of  the  basin.     At  the  end  of  each  branch  of  the 


influent-pipe  is  a  deflector  which  gives  a  horizontal  radial  direction 
to  the  water  in  a  direction  away  from  the  valve-chamber. 


RIVER-WATER  SUPPLY. 


177 


Under  normal  working  conditions  the  raw  water  entering  the 
bottom  of  division  i  through  the  1 2-inch  influent-pipe  just  de- 
scribed, displaces  an  equal  volume  of  the  surface-water  which 


passes  into  the  adjoining  quarter  division  of  the  gate-chamber 
through  a  notch  in  the  octagonal  wall  admitting  of  a  stream 
about  6  inches  deep  and  12  feet  long.  In  passing  through  this 


i78 


WATER-SUPPLIES. 


notch  the  coagulant  solution  is  introduced  through  a  series  of 
J-inch  pet-cocks  tapped  into  a  2-inch  coagulant-pipe.  From  the 
quarter  division  of  the  gate-chamber  the  water  passes  into  a 
branch  pipe  in  the  division-wall  of  the  gate-chamber  and  enters 


^C"  Vent  Pipe                                               ,£1.000.5 

(p  (P  •>  fp  £  W-  P-  . 

0 

\m 

SECTION  B-B 


^- El.  614 


j}:==j:j=|t^=^  S- — ---jr ------^--=---- 

-----A------^ 


the  influent-pipe  of  division  2  of  the  settling-basin,  which  con- 
veys it  into  basin  2,  where  it  is  deflected  horizontally  and 
radially  as  described  above  for  division  i.  The  return-flow  of 
the  displaced  water  of  division  2  enters  a  second  quarter  of  the 


RIVER-WATER  SUPPLY. 


179 


gate-chamber  by  overflowing  a  second  section  of  the  octagonal 
wall,  or  that  between  the  two  division-walls  of  the  basin;  whence 
it  enters  through  a  sluice-gate  the  influent-pipe  of  division  3, 


which  pipe  distributes  the  water  in  division  3  in  a  manner  similar 
to  that  described  for  divisions  I  and  2. 

The  water  from  division  2  can  be  given  a  second  treatment  of 


i8o  WATER-SUPPLIES. 

the  coagulant  solution  in  passing  into  the  gate-chamber  in  the 
manner  described  for  the  first  treatment. 

When  division  2  is  empty  for  cleaning  the  effluent  from  division 
i  passes  from  the  irregular  quarter  of  the  gate-chamber  into  the 
square  quarter  of  the  same  chamber  through  a  sluice-gate,  thence 
by  pipe  connection  into  the  influent-pipe  of  division  3.  The  valve 
manipulation  for  the  other  two  basin  combinations  can  be  readily 
seen  from  the  plans. 

The  drain-pipe  from  each  of  the  three  divisions  of  the  settling- 
basin,  as  well  as  the  drain-pipe  from  each  of  the  four  divisions 
of  the  gate-chamber,  enters  a  circular  drain-well  concentric  with 
the  gate-chamber  (illustrated  on  the  section  elevation  of  the  gate- 
chamber,  Fig.  26) ;  thence  the  drainage  is  conveyed  by  a  i6-inch 
cast-iron  pipe  to  the  Missouri  River. 

The  pipe  and  valve  system  of  the  filters  is  shown  in  Fig. 
25.  Each  filter  has  an  independent  influent-pipe  from  division 
3,  also  a  common  1 2-inch  influent-pipe  connecting  with  a  division 
of  the  gate-chamber  for  use  when  division  3  is  being  cleaned. 

The  plan  affords  such  a  centralization  of  the  pipe  and  valve 
system  of  the  entire  purification  works  that  a  single  attendant 
can  readily  attend  to  all  valve  manipulation  under  practically  the 
same  roof. 

The  filter-walls  are  of  reinforced-concrete  construction,  as  shown 
by  the  illustrations. 

A  distributing  reservoir  of  1,453,000  gallons  capacity  was 
designed  to  be  constructed  on  an  elevation  above  the  barracks 
about  one  mile  or  more  from  the  purification  plant.  A  plan  and 
section  of  this  reservoir  are  shown  in  Fig.  27.  Both  the  reser- 
voir and  the  clear-water  basin  connecting  with  the  filters  are  de- 
signed to  be  roofed  with  reinforced  concrete  resting  on  similarly 
constructed  girders  and  pillars  and  covered  with  about  two  feet 
of  earth,  the  roof  construction  being  identical  in  both  instances. 
The  detailed  drawings  in  Fig.  28  suffice  to  show  the  proposed 
manner  of  erecting  the  molds  and  of  constructing  the  roof.  It  will 
be  observed  that  the  roof  is  designed  in  wholly  independent  panels 
14  feet  square,  with  four  panels  cornering  on  each  pillar. 

In  passing  it  may  not  be  amiss  to  state  that  the  business  enter- 
prise of  the  men  who  have  been  interested  in  mechanical-filter 


RIVER-WATER  SUPPLY,  181 

patents  has  contributed  very  greatly  to  the  advancement  of  mechan- 
ical nitration  to  its  present  position  in  the  art  of  water  purification. 
It  served  to  bring  mechanical  filtration  before  the  public  and  to 
hold  the  attention  of  the  public  for  years  even  before  the  merits 
of  the  mechanical  filter  had  been  thoroughly  developed.  Not- 
withstanding the  efforts  of  mechanical-filter  partisans  to  exploit 
the  mechanical  filter  and  to  give  it  wide  publicity,  they  often 
obscured  the  true  merits  of  the  filter  in  a  decidedly  foggy  atmos- 
phere because  of  their  neglect  to  accord  consideration  of  the 
technical  features  which  successful  nitration  naturally  embraces, 
and  it  was  not  until  the  technical  features  of  mechanical  nitration 
and  of  the  mechanical  devices  which  are  necessary  to  insure  suc- 
cessful operation  of  a  mechanical  filter  had  been  thoroughly 
studied  that  it  was  brought  to  its  present  standard  of  excellence. 
It  has  been  clearly  shown  by  extended  experiments  and  by  close 
analytical  study  that  mechanical  filtration,  like  slow  sand  filtration, 
requires  a  thorough  advance  preparation  of  the  raw  water  before 
it  is  in  a  proper  condition  to  enter  the  filter.  The  one  is  intended 
to  be  as  much  a  refining  process  as  is  the  other;  as  good  results 
may  be  expected  from  one  as  from  the  other;  and  the  perform- 
ance of  the  one  method  of  filtration  over  the  other  is  often  a 
matter  of  adaptability  and  of  cost. 

It  may  be  safely  said  from  a  purely  technical  standpoint  that 
with  a  sufficient  advance  preparation  of  the  raw  river-water 
either  method  of  filtration  can  be  used  in  any  locality,  even  where 
such  waters  as  that  derived  from  the  Missouri,  Mississippi,  or  Ohio 
River  are  to  be  purified.  It  is  found,  however,  that  slow  sand 
filtration  together  with  the  necessary  subsiding  basins  for  the 
proper  preparation  of  the  water  for  these  filters  involves  so  great 
an  expense  as  to  be  practically  prohibitive;  and  it  is  further 
believed  that  slow  sand  niters,  when  used  in  connection  with 
purification  works  which  require  so  thorough  an  advanced  treat- 
ment of  the  raw  water  as  that  of  the  river  just  named,  become  in 
themselves  purely  mechanical  filters,  for  the  reason  that  the  long 
period  of  subsidence  and  the  large  amount  of  coagulation  to  which 
waters  from  such  rivers  must  be  subjected  doubtless  remove  from 
the  raw  water  the  elements  or  properties  which  are  needed  to  con- 


1 82  WATER-SUPPLIES. 

struct  the  filtering  mantle  which  is  supposed  to  be  the  effective 
element  in  the  operation  of  the  slow  sand  biological  filter. 

In  drawing  this  chapter  to  a  close  it  may  be  briefly  stated  as  a 
summary  of  what  has  been  said  that  natural  subsidence,  coagula- 
tion, and  nitration  are  necessary  for  the  proper  purification  of  the 
water  from  detrital  rivers  generally,  and  that  there  must  be  not 
only  a  high  standard  of  purity  for  the  effluent  of  a  filter,  but 
also  a  restricted  range  of  turbidity  to  the  filter-influent  water. 
Without  proper  regard  to  the  principles  embraced  in  the  three 
distinct  processes  and  to  the  bacterial  and  physical  condition 
of  the  water  admitted  to  a  filter  it  is  found  impossible  to  secure 
a  water  of  uniform  purity,  or  one  that  should  be  recognized 
as  conforming  to  a  proper  standard  for  a  good  and  wholesome 
water.  The  general  practice  of  the  present  day  is  not  up  to  the 
standard  indicated.  Principles  are  often  disregarded,  especially 
the  one  of  preliminary  preparation  of  the  water  for  filtration,  car- 
ried even  to  the  extent  of  sometimes  adding  a  coagulant  to  a 
water  of  very  low  turbidity  in  order  to  make  filtration  success- 
ful even  through  slow  sand  filters.  If  the  author  has  succeeded 
in  making  this  point  clear  and  in  helping  on  the  work  of  reform 
in  the  directions  indicated,  it  is  believed  that  the  chief  obstacle  to 
successful  water  purification  by  filtration  can  be  overcome. 


CHAPTER  in. 

PUMPING-ENGINES. 

THE  pumping-engine  is  so  important  a  part  of  the  equipment 
of  many  water-works  as  to  warrant  a  few  words  regarding  its  use 
and  maintenance.  Little  can  be  said  regarding  the  manufacture 
of  machinery  of  this  kind,  as  it  is  a  special  work  carried  out  by 
corporations  fully  equipped  to  design  and  manufacture.  The 
manufacturers,  however,  desire  a  thorough  knowledge  of  the  ser- 
vice in  which  a  pumping-engine  is  required  to  work  in  practice,  of 
the  source  of  the  water-supply,  and  of  any  physical  conditions 
which  may  affect  the  installation  of  the  machine  and  the  service 
expected  of  it. 

Accordingly  the  engineer's  specifications  under  which  pro- 
posals of  design,  installation,  and  manufacture  are  invited  and 
the  purchase  is  made  are  usually  confined  to  general  stipula- 
tions defining  and  fixing  the  obligations  of  the  contracting 
parties,  a  detailed  statement  of  the  conditions  affecting  both  the 
installation  and  operation  of  the  pumping-machinery  as  above 
outlined,  and  the  terms  of  payment,  etc.  Frequently  a  certain 
type  of  machine  is  specified  which  is  known  to  possess  superior 
merits  for  a  particular  kind  or  range  of  service.  Usually  plans 
are  submitted  with  the  specifications  to  illustrate  the  description 
given  therein  and  to  show  the  design  and  arrangement  of  the 
pumping-station,  together  with  the  arrangement  of  plant  and 
machinery  already  installed  or  about  to  be  installed. 

It  is  usually  customary  for  the  purchaser  to  build  the  founda- 
tions upon  which  the  machinery  is  to  rest  after  plans  of  the  manu- 
facturer showing  the  anchor-bolt  lay-out  and  the  design  of  the  super- 

183 


1 84  WA TER  SUPPLIES. 

structure  to  accommodate  the  type  of  machine  proposed  for  instal- 
lation. Such  a  division  of  the  work  serves  to  facilitate  matters  and 
to  reduce  expense. 

The  manufacturer,  while  providing  the  valves,  fittings,  and  ac- 
cessories necessary  to  properly  govern  and  operate  the  machinery, 
is  seldom  expected  to  carry  his  work  outside  the  walls  of  the 
building  in  which  the  machinery  is  installed. 

Usually  the  purchaser  requires  of  the  manufacturer  some  sort 
of  guarantee  as  to  the  degree  of  economy  with  which  a  proposed 
pumping-engine  will  perform  the  work  of  pumping  water.  Evi- 
dently the  larger  the  number  of  gallons  of  water  delivered  by  the 
pumps  of  a  pumping-engine  with  the  consumption  of  some  given 
amount  of  fuel  under  the  boilers  or  of  steam  by  the  engine,  as  the 
case  may  be,  the  less  becomes  the  fuel  expense  and,  relatively,  the 
higher  the  economy  of  the  machine  becomes  in  operation.  The 
measurable  work  of  the  pumps  never  accounts  for  all  of  the  energy 
developed  by  the  combustion  of  coal  in  the  boiler-furnaces  in  the 
manufacture  of  steam,  nor  even  for  all  of  the  energy  in  the  steam 
admitted  to  the  steam-cylinders  of  the  engine  actuating  the  pumps, 
for  a  large  portion  of  the  heat  of  the  coal  is  unavoidably  wasted, 
and  also  a  portion  of  the  heat  energy  actually  absorbed  by  the  steam 
is  unavoidably  lost  in  passing  through  the  pipes  leading  to  the 
engine,  in  the  steam-cylinders  themselves,  and  in  overcoming  the 
friction  of  the  moving  parts  of  the  machinery  which  it  actuates. 
Accordingly  in  practice  the  term  "mechanical  efficiency "  is 
applied  to  pumping-engines,  meaning  thereby  the  relation  which 
the  work  actually  done  by  the  steam  in  the  cylinders  bears  to 
the  work  actually  accomplished  by  the  pumps  in  lifting  water. 
Thus  if  the  work  done  by  the  pumps  divided  by  the  indicated  work 
in  the  steam-cylinder  equals  unity,  as  would  be  the  case  were  the 
actual  and  the  indicated  work  the  same,  then  the  engine  is  perfect 
mechanically  and  the  mechanical  efficiency  is  100  per  cent.  But 
as  this  percentage  measure  of  mechanical  efficiency  decreases  the 
work  of  the  engine  decreases  on  the  scale  of  economy;  for  instance, 
a  machine  giving  a  mechanical  efficiency  of  90  per  cent  is  better 
designed  and  constructed  than  one  giving  70  per  cent. 

But  the  ordinary  term  for  a  measurement  of  economy  of  a 
pumping-engine  is  "  duty  "  in  terms  of  foot-pounds — meaning  the 


PUMPING-ENGINES.  185 

number  of  pounds  of  water  a  pumping-engine  is  capable  of  lifting 
one  foot  high  with  the  expenditure  of  a  unit  volume  of  fuel  or 
steam.  Formerly  the  unit  volume  was  100  pounds  of  coal  or 
combustible.  This  basis  of  measurement  is  unsatisfactory  to 
both  the  manufacturer  and  the  purchaser  of  a  pumping-engine 
because  it  necessarily  embraces  the  evaporative  capacity  of  the 
boilers  and  the  mechanical  perfection  of  the  boiler-setting  and 
steam-piping  connecting  the  boilers  with  the  pumping-engine.  In 
other  words,  the  pumping-engine  ceases  to  be  a  unit  of  consideration 
in  itself  in  a  duty  test.  And  from  the  very  nature  of  the  combi- 
nation of  engine,  piping,  boilers,  and  furnaces,  it  is  sometimes 
difficult  and  embarrassing  to  fix  responsibility  for  failure  of  an 
engine  to  give  a  stated  duty  when  the  several  units  of  the  com- 
bination are  the  workmanship  of  as  many  different  contractors, 
Moreover  the  technical  details  to  be  observed  and  the  measure- 
ments to  be  taken  in  a  combined  test  are  many  and  often  con- 
siderably complicated. 

Of  late  years  it  has  been  customary  to  use  the  unit  volume  as 
one  thousand  pounds  of  steam  delivered  to  the  engine  at  some 
stated  pressure.  The  choice  of  this  unit  of  volume  simplifies  mat- 
ters, and  by  isolating  the  boiler  or  boilers  furnishing  steam  for  the 
engine  under  test,  or  by  measuring  the  amount  of  steam  diverted 
from  the  engine  under  test  for  use  in  other  directions,  the  obser- 
vations and  measurements  relating  to  a  test  are  rendered  less 
complicated  than  in  the  former  case  just  described.  This  method 
of  measuring  the  duty  of  a  pumping-engine,  while  satisfactory 
from  a  purchaser's  or  a  manufacturer's  point  of  view,  does  not  meet 
the  requirements  altogether  for  ordinary  station  practice,  for  the 
reason  that  it  fails  to  show  a  direct  relation  between  the  work  done 
in  pumping  water  and  in  operating  other  station  appurtenances 
and  the  coal  consumed  under  the  boilers.  Consequently  for  sta- 
tion purposes  it  is  often  convenient  to  refer  to  economy  in  vari- 
ous terms,  as  steam  consumption  per  horse-power  per  hour,  coal 
consumed  per  horse-power  per  hour  and  coal  consumed  per  1000 
gallons  of  water  raised  a  given  height,  etc. 

In  order  to  facilitate  computations  and  to  compare  approxi- 
mately the  various  units  of  measurements  the  following  formulae 
and  tables  are  offered: 


186  WATER-SUPPLIES. 

Let  D  =  duty  of  pumping-engine  in  foot-pounds  per  1000  pounds 

of  steam  consumed  by  engine; 

#=head  or  total  lift  of  pump,  including  suction-lift; 
F= volume  of  water  pumped  per  unit  of  time;    say,  for 

convenience,  one  hour; 
W — weight  of  unit  of  volume  of  water,  8.34  pounds  per 

U.  S.  gallon; 

S= weight  of  steam  consumed  per  hour; 
H.P.=pump    horse-power.     One    H.P.=  33,000    ft.-lbs.    of 

work  per  minute  or  1,980,000  ft.-lbs.  per  hour; 
C=coal  consumed  per  H.P.  per  hour. 

HxVXWXiooo 
Thus  £>  =  - 


H.P. 


5 
HXVXW 


1980000 
D        1000X1980000 


S        1000X1980000 
HJ>=-         D 

S  1980 

or 


H.P.     duty  in  million  ft.-lbs. 

=  steam  consumption  per  horse-power  per  hour. 

From  the  last  equation  the  following  table  is  computed: 

STEAM  CONSUMPTION  PER  PUMP  H.P.  PER  HOUR  FOR  STATED  DUTIES  IN 
MILLION  FOOT-POUNDS. 


10 

15 

20 

25 

3° 

35 

40 

5° 

60 

198 

132 

99 

79.2 

66 

56.6 

49-5 

39-6 

33 

70 

80 

9° 

100 

no 

120 

130 

140 

150 

28.3 

24.7 

22.0 

19.8 

18.0 

I6.5 

15.2 

14.1 

13-5 

COAL  CONSUMPTION  PER  PUMP  H.P.  PER  HOUR,  AT  AN  EVAPORATION  OF 
10  POUNDS  OP  WATER  PER  POUND  OF  COAL,  OR  WHEN  C  =  S/io  H.P., 
FOR  STATED  DUTIES  IN  MILLION  FOOT-POUNDS. 


10 

19.8 

15 
13.2 

20 
9.9 

25 
7.92 

3° 
6.6 

35 
5.66 

40 
4-95 

5° 
3-96 

60 
3-3 

70 

2.83 

80 

2.47 

90 
2  .  2 

IOO 
1.98 

no 

1.8 

120 

I30 
1.52 

140 
1.41 

x'.W 

PUMPING-ENGINES.  187 

To  illustrate  the  use  of  the  table,  suppose  that  a  pumping 
engine  was  found  to  consume  22  pounds  of  steam  per  pump  horse- 
power per  hour,  as  measured  by  the  weight  of  water  evaporated 
by  the  boiler,  and  also  that  the  boiler  was  found  to  evaporate  6 
pounds  of  water  per  pound  of  coal.  The  duty,  then,  by  the  table 
would  be  90  million  foot-pounds  per  1000  pounds  of  steam  or  per 
100  pounds  of  coal  on  the  basis  of  an  evaporation  of  10  pounds  of 
water  per  pound  of  coal,  or  54  million  foot-pounds  per  100  pounds 
of  coal  consumed  under  the  boiler,  and  the  coal  consumed  per 
pump  horse-power  per  hour  would  be  about  3.6  pounds. 

In  every  pumping-station  a  record  should  be  kept  of  the 
amount  of  coal  consumed  in  the  boiler-furnaces  and  the  number 
of  revolutions  made  by  each  unit  of  the  pumping-machinery  and 
of  the  head  or  pressure  against  which  the  pumps  operate,  for  infor- 
mation of  this  kind  systematically  and  methodically  recorded 
enables  an  engineer  to  keep  posted  upon  the  station  duty  of  the 
several  machines  under  his  charge. 

The  station  duty  is  found  to  vary  considerably  from  the  test 
duty  usually  embodied  in  specifications  governing  the  purchase 
of  a  pumping-engine,  for  the  station  duty  is  usually  based  upon 
a  unit  volume  of  the  coal  consumed  and  often  takes  into  account 
boiler  economy,  waste,  and  the  fuel  consumed  for  all  auxiliary 
engines  as  well  as  for  the  pumping-engines  actually  delivering  the 
water  into  the  distributing  pipes.  For  instance,  in  a  pumping- 
station  recently  inspected  it  was  found  that  one  pumping-engine 
which  on  test  delivered  338  gallons  of  water  per  pound  of  fuel 
actually  delivered  in  daily  service  263  gallons  of  water  for  every 
pound  of  fuel  consumed,  that  a  combination  of  large  and  small 
pumping-engines  delivered  156  to  172  gallons  of  water  per  pound 
of  coal,  and  that  the  average  annual  station  duty  for  a  period 
of  three  years  was  from  150  to  167  gallons  of  water  per  pound 
of  coal  consumed.  It  was  also  observed  when  a  proper  correction 
was  made  for  the  slips  of  the  pumps  that  the  station  duty  became 
reduced  for  one  year  to  124  gallons  of  water  per  pound  of  fuel 
consumed.  The  working  head  against  the  pumps  was  about  323 
feet. 

Thus  it  is  observed  that  a  test  duty  may  be  much  in  excess  of 
the  ordinary  station  duty  and  that  when  attendants  become 


i88 


IV A  TER-SUPPLIES. 


careless  or  helpless  regarding  the  mechanical  condition  of  the 
pumping-engine  the  station  duty  based  upon  coal  consumed  and 
water  actually  delivered  into  the  mains  may  run  very  low. 

Attendants  may  find  it  convenient  to  have  a  table  or  diagram 
showing  the  station  duty  of  the  pumping-machinery  per  pound 
of  fuel  consumed  when  the  head  or  pressure  against  which  the 
pumps  operated  is  known.  A  diagram  of  this  kind  may  be  found 
on  page  189. 

On  other  occasions  when  the  annual  amount  of  fuel  to  be 
charged  against  some  specific  unit  volume  of  water,  as  1000  gal- 
lons, is  desired  the  diagram  on  page  189  maybe  found  convenient. 

Again,  the  annual  cost  of  fuel  per  one  million  gallons  of  water 
raised  some  stated  height,  when  the  station  duty  is  known, 
is  another  convenient  unit  often  referred  to;  accordingly  two 
diagrams  on  page  190  may  be  of  service.  The  diagrams  are 
based  upon  300  feet  head  or  130  pounds  gauge  pressure,  but  a 
reduction  to  any  particular  working  head  in  feet  may  be  made 
by  multiplying  the  annual  fuel  cost  as  ascertained  from  the 
diagram  by  the  ratio 

Particular  head  in  feet 
300 

A  method  of  keeping  the  pumping-station  records  is  given 
below.  It  may  be  varied  somewhat  to  suit  local  requirements. 


DAILY  STATION  RECORD  OF  PUMPING-ENGINES. 

Date .  . 


Description. 

Nominal 
capacity. 

Hours  of 
service. 

Counter  reading. 

Gallons 
of 
water 
pumped. 

Water 
pressure. 

Steam 
pressure. 

Vacuum. 

Starting 

Stop- 
ping. 

PUMPING-ENGINES. 


189 


»  300  400  500  600  700  800  900  1000  1100  .1200  1300  1400  1500  1600  1700  1800  1900  2000 

Gallons  of  Water  Raised  per  Pound  of  Coal  Consumed 


FlG.  29. 


12      4      6      8      10     12     14    16     18     20     22     24     26     28     30     32     34     36     38     40 
Amount  of  GoaTm  Hundred  Weight 

FIG.  30. — Amount  of  Coal  Required  Annually  to  Raise  1000  Gallons  of 

Water  Daily 


190 


WATER-SUPPLIES. 


'$1000 


6        7        8        9       10      11      12      13      \i      J5      16      17      18      19      20 
Annual  Cost  of  Fuel  in  .Thousand  Dollars 


FIG.  31. — Annual  Cost  of  Fuel  Required  to  Raise  1,000,000  Gallons  of 
Water  Daily  300  Feet  High,  allowing  5%  for  Slip. 


.$1000 


3  3  4         >     5  6  7 

Annual  Cost  of  Fuel  in  Thousand  Dollars 


FIG.  32. — Annual  Cost  of  Fuel  Required  to  Raise  1,000,000  Gallons  of 
Water  Daily  300  Feet  High,  allowing  5%  for  Slip. 


PUMPING-ENG1NES. 


191 


DAILY  STATION  RECORD  OF  BOILERS. 

Date. 


Description. 

Hours 
in 
service. 

Steam 
pressure. 

Temperature. 

Fuel. 

Remarks. 

Feed- 
water. 

Flue- 
gases. 

Coal. 

Ashes. 

A  table  has  been  prepared  based  upon  data  collected  from  the 
annual  reports  of  water  departments  for  the  purpose  of  illustrating 
the  station  duties  that  may  be  expected  from  various  types  of 
pumping-engines. 

TACLE  XI. 


s 

Pounds 

•8 

No.  of 
pump- 
ing 
days. 

consumed 
in  raising 
steam  in 
per  cent 
of  total 
coal  con- 

Average 
head 
against 
pump. 

Gallons 
of  water 
pumped 
per  pound 
of  coal. 

of  coal 
required 
to  raise 
1000  gal- 
lons of 
water  to 

Annual  engine 
duty  per 
loo  pounds 
of  coal  con- 
sumed. 

Remarks. 

1 

sumed. 

stated 
height. 

i 

IOO 

190 

5-3 

15786000^ 

Ordinary  duplex 
comp.  condens- 

10 

IOO 

0.51 

176.5 

152 

6.64 

22370000  J 

ing 

i 

6.08 

173.2 

288 

3-48 

High-grade 

comp.    cond. 

duplex 

ii 

IO 

302.4 
126.6 

6-33 
2.82 

242 
181 

259-3 

335-7 

3-86 
2.982 

52273000 
50725500 

Holly  quad. 
Cornish  beam 

I 

152.8 

406.8 

2.458 

51843600 

Rotative  duplex 

comp.  condens- 

I 

365 

61.69 

638.2 

1.56 

32807533 

do. 

I 

52.5 

1162  .  5 

0.86 

50870200 

Vert,     marine 

type 

7 

360.6 

o.  26 

184.89 

792.52 

1.264 

122076700 

H  igh  -  grade 

vert. 

It  will  be  observed  from  the  preceding  table  that  the  head 
against  which  a  pumping-engine  works  is  an  important  factor  in 
comparing  economy  of  operation  and  that  if  one  is  to  draw  fair 
comparison  the  work  of  the  engines  should  be  based  upon  a  com- 
mon head  of  say  100  feet.  Making  this  reduction  we  find  the  pounds 


1 92  WATER-SUPPLIES. 

of  coal  required  to  raise  1000  gallons  of  water  100  feet  high  for 
the  several  types  of  engines  referred  to  are  respectively  as  follows: 
5-3,  3-76>  2-OI>  T-59>  1-65,  1-61,  2.53,  1.64,  0.68. 

The  above  table  and  succeeding  computations  should  not  be 
accepted  as  truly  comparable,  for  unless  all  the  conditions  of  service 
are  known  in  each  instance  and  an  allowance  made  accordingly 
unfair  comparison  may  result.  All  that  is  desired  by  the  illustra- 
tion is  an  approximate  comparison  of  the  several  types  of  engine. 
For  instance  the  same  type  of  engine  working  in  direct-pressure 
service  would  not  give  as  high  a  duty  as  when  working  under  the 
conditions  of  reservoir  service  for  the  reason  that  in  the  former 
instance  the  speed  of  the  engine  fluctuates  with  the  momentary 
and  hourly  requirements  of  service,  while  in  the  latter  case  the 
engine  may  operate  under  full  load  at  its  most  economical  speed 
hour  after  hour  and  day  after  day,  regardless  of  the  rate  of  water 
consumption. 

It  is  not  easy  to  obtain  pumping-station  duties  of  the  small 
water-works  which  use  the  non-condensing  duplex  type  of  pumping- 
engines  for  the  reason  that  in  the  majority  of  cases  the  records  are 
incomplete. 

The  slip  of  pumps  embraces  the  water  which  in  the  operation 
of  a  pumping-engine  escapes  through  leaky  or  defective  valves  or 
churns  backward  and  forth  through  a  defective  plunger  packing ; 
that  is  to  say,  it  is  that  portion  of  the  pump-plunger  displacement 
which  does  not  reach  the  distributing  system  although  raised  to  a 
pressure  corresponding  to  that  of  the  portion  which  does  enter  the 
distributing  main.  It  requires  proportionately  as  much  fuel  to 
support  the  slip  of  a  pump  as  it  does  the  delivery  of  the  pump. 
For  instance,  to  take  an  exaggerated  case,  if  the  slip  of  the  pump  is 
50  per  cent,  then  one-half  the  fuel  consumed  in  running  the  pump- 
ing-engine  would  be  used  in  supporting  slip  and  one-half  in  deliver- 
ing water  into  the  force  main,  or  the  annual  cost  of  fuel  would  be 
nearly  double  what  it  should  be  were  the  pumps  maintained  in 
an  efficient  condition.  It  is  surprising  to  see  the  inefficient  con- 
dition which  pumping-machinery  is  sometimes  allowed  to  reach. 
To  illustrate  this  condition  reference  is  made  to  a  controversy 
which  arose  a  few  years  ago  between  a  municipal  corporation 
owning  its  own  water-works  and  a  private  corporation  dependent 


PUMPING-ENG1NES.  193 

upon  the  former  corporation  for  its  supply  of  water  delivered  to 
the  company's  distributing-pumps  at  a  very  low  pressure.  The 
controversy  of  three  years'  standing  related  to  the  actual  delivery 
of  a  pumping-engine  of  9  or  10  million  gallons  capacity  per  24 
hours  for  the  stated  period  of  years  and  involved  a  considerable 
sum  of  money.  A  commission  was  finally  appointed  to  arrive  at 
the  facts  and  to  settle  the  controversy. 

Three    independent    methods    of   measurement    were    finally 
adopted  by  the  commission: 

1.  The  plunger-displacement  method,  with  the  pump  operating 
against  a  tightly  closed  gate-valve  on  the  force  main.     This  method 
of  slip  measurement  was  acceptable  to  the  owners  of  the  machine 
and  the  purchaser  of  the  water,  but  discarded  by  the  party  selling 
the  water. 

2.  The  piezometer  method,  by  means  of  which  a  series  of  hy- 
draulic grade  lines  were  determined  on  the  very  low-pressure 
flow-line  furnishing  water  to  both  parties,  into  which   a  meas- 
urable and  known  quantity  of  water  was  delivered.     The  hydraulic 
gradients  were  established  both  above  and  below  the  point  from 
which  the  volume  of  water  in  dispute  was  abstracted. 

3.  A  weir  measurement  of  the  actual  amount  of  water  delivered 
by  the  pumping-engine  in  question  when  operated  at  different 
speeds  under  the  pressure  conditions  corresponding  to  regular 
service.     The   difference   between   the   nominal   delivery    of   the 
pumps  based  upon  plunger  displacement  and  the  actual  delivery 
as  measured  by  the  weir  gave  the  slip. 

The  slip  of  the  pumps  as  measured  by  these  totally  different 
and  independent  methods  is  as  follows: 

1.  Displacement  method 2872.34  gallons  per  minute 

2.  Piezometer  method 3090.00 

3.  Weir  method 2926.46 


Average  of  the  three  methods . .  2962 . 9    gallons  per  minute 

The  average  computation  of  the  slip  was  accepted  as  correct, 
and  the  test  proved  the  substantial  accuracy  of  the  displacement 
method  of  slip  measurement,  and  enabled  the  commission  to 
employ  various  similar  measurements  of  slip,  previously  taken,  in 


194 


IV A  TER-SUPPLIES. 


the  construction  of  a  diagram  used  in  the  correction  of  the  records 
of  the  three  preceding  years  and  to  arrive  at  the  actual  delivery, 
which  was  found  to  aggregate  nearly  1960  million  gallons  of 
water  and  the  slip  to  aggregate  nearly  as  much. 

The  condition  of  the  pumps  at  the  time  of  the  test  is  repre- 
sented by  the  following  table  based  upon  weir  measurement. 


Test  number. 

Revolutions  per  minute. 

Nominal  delivery  in 
gallons  per  minute. 

Percentage  which 
actual  delivery  was  of 
nominal  delivery. 

I 

8.8 

2702.79 

0.0 

2 

10.  0 

3102.47 

4-5 

3 

10.6 

3338.09 

II  .  2 

4 

II  .  2 

35°7-i2 

15-5 

5 

12  .O 

3786.97 

21.8 

6 

12.8 

4059.3S 

27.0 

7 

14.13 

4412.05 

32-8 

8 

14-5 

4543-70 

38.8 

9 

15-4 

4702.51 

36.9 

10 

16.8 

5309.22 

44-2 

ii 

18.2 

5751-66 

48.5 

It  is  obvious  from  the  table  that  the  fuel  required  to  raise 
the  2702.79  gallons  per  minute  of  water  to  the  pressure  of  distri- 
bution was  absolutely  wasted.  This  glaring  example  of  waste 
through  slip  serves  to  illustrate  forcibly  the  importance  of  timely 
repairs  of  the  moving  parts  of  the  pumps. 

Moreover  the  comparative  tests  show  that  the  displacement 
method  of  measuring  slip  by  operating  against  a  closed  valve  on 
the  force-main  under  the  pressure  conditions  of  service  is  suffi- 
ciently accurate  for  practical  purposes.  It  has  the  further  value 
of  being  applied  in  any  pumping-station  with  little  or  no  expense. 

The  valves  in  the  force  and  suction  chambers  of  the  pumps 
become  the  source  of  serious  slip  whenever  the  valve-seats  are 
allowed  to  become  scored  or  the  rubber  disks  unusually  worn,  and 
either  one  of  these  two  causes  will  lead  to  the  presence  of  the  other. 
Usually  the  diameter  of  the  pump- valves  is  about  3^  inches,  and 
unless  the  rubber  disks  are  capped  with  a  metal  plate  of  somewhat 
smaller  diameter  they  open  over  the  radial  arm  of  the  valve-seats 
under  heavy  pressure  and  allow  the  escape  of  water  at  each  stroke 
of  the  pump.  Prolonged  leakage  of  this  character  under  high 
pressure  eventually  scores  the  valve-seats  and  cuts  the  valve- 


PUMPJNG-ENGINES.  195 

disks  irregularly — so  much  so  that  the  hissing  sound  of  water 
escaping  through  the  valves  is  often  distinctly  audible. 

The  lift  of  the  valves  should  never  be  much,  for  the  wear  and 
tear  of  pump-valves  depends  not  only  upon  the  number  of  re- 
versals of  the  pump-plunger,  but  also  upon  impact  at  the  instant 
the  direction  of  the  stroke  of  the  plunger  reverses.  The  impact 
becomes  most  serious  when  the  pumps  are  forced  beyond  their 
rated  capacity. 

Little  need  be  said  about  the  size  and  lift  of  pump- valves,  as 
the  purchaser  can  scarcely  define  details  of  this  character  precisely 
without  assuming  responsibility,  in  a  measure  at  least,  for  the 
design  of  the  machine  and  proportionately  for  the  results  of  opera- 
tion. These  details  are  usually  left  to  the  judgment  of  the  manu- 
facturer under  reasonable  guarantees  of  maintenance  and  renewals 
of  broken  or  defective  parts  for  some  specific  period  of  time.  Gen- 
erally speaking  this  course  of  procedure  duly  protects  the  inter- 
ests of  both  the  purchaser  and  the  manufacturer  if  the  purchaser's 
specifications  define  with  proper  precision  the  actual  conditions 
of  service.  If  these  conditions  are  not  so  defined,  it  is  scarcely  con- 
ceivable that  the  interests  of  the  purchaser  would  be  better  or 
more  safely  served  by  interfering  with  the  details  of  design  except 
through  the  instrumentality  of  a  master  of  the  art  of  design. 

Loss  by  slip  through  the  plunger  packing  is  much  more  liable 
to  be  neglected  in  pumps  internally  packed  than  in  those  externally 
packed,  for  the  reason  simply  that  any  lack  of  vigilance  on  the 
part  of  an  attendant  is  less  apparent  in  the  former  than  in  the 
latter  case  and  correspondingly  less  liable  to  correction  by  an 
overseer,  and  for  the  additional  reason  that  many  inside-packed 
pumps  are  metal-packed  and  cannot  be  repaired  except  by  lathe- 
work,  for  which  class  of  work  most  small  water-works  are  not 
prepared.  Accordingly  wear  is  frequently  allowed  to  progress  to 
an  extent  which  under  more  favorable  circumstances  for  repairs 
and  better  facilities  for  packing  would  not  be  tolerated. 

It  might  be  observed  that  inside  metal-packed  pumps  are  only 
adapted  to  the  pumping  of  water  entirely  free  from  dirt,  and  even 
when  used  in  pumping  clear  water  under  moderate  pressure  it  is 
profitable  to  make  a  timely  purchase  of  duplicate  plunger  and 
rings  to  replace  the  old  ones  as  they  become  worn  sufficiently  to 


196  WATER-SUPPLIES. 

admit  of  pronounced  slip.  The  old  ones  can  always  be  repaired 
in  some  near-by  city  if  no  facilities  are  available  at  home  for  the 
purpose. 

The  lowest-grade  pumping-engine  on  the  score  of  economy  that 
is  permissible  to  install  in  a  water-works  for  daily  service  is  the 
compound,  non-condensing,  duplex  pumping-engine.  The  low 
economy  of  this  class  of  machinery  is  offset  in  a  great  measure  by 
its  low  cost  and  simplicity  of  design  and  operation,  which  makes 
it  popular  with  small  communities  for  the  first  five  to  ten  years  of 
experience  with  water-works.  In  fact  it  is  peculiarly  adapted  to 
the  conditions  and  circumstances  surrounding  the  introduction 
of  water-works  in  small  towns,  because  its  simplicity  of  construction 
renders  it  the  least  likely  of  disarrangement  under  the  direction 
and  supervision  of  a  very  ordinary  mechanic  and  occasions  the 
least  expense  for  maintenance  and  repairs,  and  because  economy 
of  operation  is  of  small  consideration  for  the  very  few  hours 
of  service  daily  during  the  probationary  period  which  serves 
to  render  a  community  acquainted  with  the  convenience,  nature, 
and  value  of  a  public  water-service,  and  to  accumulate  the  experi- 
ence and  the  proper  appreciation  of  essentials  that  are  necessary  in 
the  successful  management  of  a  water-works.  An  investment  in 
more  expensive  and  more  complicated  machinery  than  the  simple 
duplex  machine  would  sometimes  prove  unprofitable  until  proper 
experience  had  been  acquired  and  the  water-service  had  become 
extended  and  popular. 

Generally  speaking,  the  inside  metal-packed  plunger-pump  is 
preferred,  and  usually  installed  during  the  probationary  period, 
for  water-pressure  under  150  pounds  per  square  inch.  Fibrous 
packing,  sometimes  substituted  for  metal  plunger-packing,  adds  to 
the  frictional  resistance  of  the  plunger  in  operation  and  accordingly 
reduces  the  mechanical  efficiency  of  the  machine. 

For  pressures  above  150  pounds  per  square  inch  it  is  found 
economical  and  much  safer  to  approximate  as  nearly  as  possible 
a  cylindrical  form  of  construction  of  the  pump-chambers,  and 
accordingly  the  usual  form  of  design  is  four  cylindrically  formed 
pump-chambers  standing  upright  in  pairs,  and  with  a  plunger 
working  through  two  outside  stuffing-boxes  for  each  pair  of 
pump-cylinders,  as  illustrated  by  Plate  XV,  page  103.  These 


PUMP1NG-ENG1NES.  *97 

» 

stuffing-boxes  are  fibrous-packed,  usually  with  braided  Italian 
hemp,  and  show  any  slip  or  leakage  of  water  around  the  plunger. 
The  double  fibrous-packed  plunger  offers  more  than  twice  the 
resistance  of  the  single  inside  metal-packed  plunger  previously 
described.  However,  this  increased  friction  is  unavoidable  in 
high-pressure  service  and  under  careful  mechanical  supervision  it 
need  not  be  a  large  percentage  of  the  total  frictional  resistance, 
which  in  high-pressure  work  is  largely  the  pipe  resistance  of  the 
force-main  and  distributing  pipes. 

The  inside-packed  plunger  possesses  the  further  advantage  of 
being  able  to  sustain  a  higher  vacuum  on  the  pump  suction-chamber 
than  the  outside-packed  plunger,  because  the  latter  is  continuously 
exposed  to  atmospheric  pressure  and  will  allow  air  to  enter  the 
suction-chamber  of  the  pumps  through  an  imperfectly  packed 
plunger  stuffing-box  gland. 

The  duplex  pumps  wih1  often  short-stroke;  that  is  to  say,  they 
will  sometimes  run  with  a  shorter  stroke  than  that  necessary  to 
a  full-capacity  delivery  of  water.  It  is  therefore  customary  to 
have  a  stroke-adjustment  mechanism  actuated  by  hand-wheels 
communicating  by  a  spindle  with  the  interior  of  the  engine,  by 
means  of  which  an  adjustment  can  be  made  to  correspond 
with  full-stroke  delivery  as  soon  as  the  engine  after  starting  is 
well  warmed  and  the  pump  is  under  full  load. 

When  the  pumping-engine  is  working  under  heavy  pressure 
it  is  a  wise  precaution  to  have  attached  to  the  steam-valve  of 
the  engine  a  water-pressure  governor  like  the  Fisher  governor, 
which  shuts  off  the  steam  upon  a  sudden  faU  of  water-pressure 
like  the  bursting  of  the  force-main  or  similar  accident. 

The  conditions  of  service  in  many  towns  require  stand-pipe 
pressure  for  domestic  service  and  direct  pressure  for  fire  service. 
In  the  one  case  the  stand-pipe  communicates  with  the  distributing 
system  of  pipes,  absorbs  whatever  water  comes  from  the  pumps  in 
excess  of  the  consumption  and  accordingly  governs  the  pressure 
upon  the  pipe  system;  in  the  other  case  the  stand-pipe  is  valved 
off  from  the  distributing  pipes  and  no  more  water  can  be  delivered 
into  the  pipe  system  than  that  which  is  drawn  out  of  it  by  con- 
sumption through  the  house  service-pipes  or  fire-hydrants.  Ac- 
cordingly in  direct-pressure  service  the  pressure  upon  the  pipe 


1 9  8  IV A  TER-S  UPPLIES. 

system  may  be  increased  through  the  operation  of  the  boilers  and 
pumps  much  above  the  ordinary  stand-pipe  pressure.  But  a 
compound  duplex  pumping-engine  designed  to  work  economically 
under  a  stand-pipe  pressure  cannot  work  in  a  similar  manner  under 
fire-service.  This  difficulty  is  overcome  by  providing  a  valve 
which  when  opened  admits  high-pressure  steam  into  the  low-pres- 
sure cylinder  ordinarily  using  steam  expansively,  thereby  convert- 
ing the  machine  into  a  simple  engine  using  steam  altogether  at 
boiler-pressure.  For  the  time  being  all  concern  to  secure  station 
economy  in  the  use  of  fuel  is  abandoned  in  an  effort  to  furnish 
prompt  and  efficient  fire-service,  and  justifiably  so,  for  the  period 
of  fire-service,  always  comparatively  brief,  is  one  which  demands 
the  protection  of  property  exposed  to  destruction  at  any  pumping- 
station  expense  of  operation.  A  similar  adjustment  of  rotative 
pumping-engines  to  the  requirements  of  a  variable  service  is  made 
by  means  of  an  adjustable  cut-off. 

It  is  usually  customary  to  place  a  check-valve  on  the  force- 
main  near  the  pumps,  but  with  doubtful  propriety  in  small  water- 
works when  accompanied  by  a  gate-valve,  for  the  reason  that  a 
check-valve  does  not  relieve  a  pump  of  water-hammer  and  is 
unnecessary  to  keep  the  pressure  off  of  the  pump-valves  when 
the  engine  is  not  working,  as  it  takes  but  a  few  minutes  to  close  a 
stop- valve  of  12  inches  and  less  diameter;  with  water- works  having 
large  water-mains  the  situation  is  so  entirely  different  that  a 
multiple  check- valve  is  indispensable.  The  pounding  of  the  check 
may  be  a  very  disagreeable  if  not  a  dangerous  feature  usually 
experienced  when  pumps  reach  or  somewhat  exceed  their  rated 
capacity. 

A  long  force-main  connecting  the  pumps  with  the  distributing 
system  is  frequently  exposed  to  a  heavy  water-ram,  but  it  can  be 
greatly  relieved  from  the  shock  of  the  surging  water  by  a  relief- 
valve  located  usually  in  the  pumping-station.  Under  some  con- 
ditions of  service — where,  for  instance,  a  heavy  static  lift  is  required 
in  order  to  reach  a  high  elevation,  and  in  addition  where  there  is 
the  resistance  of  a  long  force-main  to  overcome — a  relief  valve  is 
absolutely  essential,  particularly  when  the  pipe-lines  are  small. 

A  grade  of  pumping-engine  next  above  that  just  described  is 
the  compound  condensing  duplex  type.  In  this  type  of  engine  the 


PUMP1NG-ENGINES.  199 

low-pressure  cylinder  is  somewhat  larger  in  proportion  to  the  high- 
pressure  cy Under  than  it  is  in  the  type  previously  described,  thereby 
admitting  of  greater  benefit  of  steam  used  expansively.  The 
exhaust-steam  passes  into  a  condenser,  where  it  is  condensed  and 
subsequently  returned  to  the  boiler  or  wasted,  as  the  case  may  be. 
Local  conditions  usually  decide  whether  a  surface  or  a  jet  condenser 
can  be  most  economically  installed  in  connection  with  the  pumping- 
engine.  The  saving  of  fuel  through  the  higher  expansion  of  steam 
in  this  type  of  pumping-engine  and  in  the  use  of  a  condenser 
should  increase  the  station  duty  fully  25  to  30  per  cent. 

A  second  step  in  advance  is  the  installation  of  a  triple-expansion 
duplex  or  a  horizontal  compound  fly-wheel  pumping-engine  of 
the  condensing  kind.  Small  units  of  either  type  of  engine  are 
now  manufactured  for  small  water-works  where  the  average  daily 
consumption  does  not  exceed  one-half  million  gallons  of  water, 
which  the  manufacturer  will  guarantee  to  give  a  test  duty  re- 
spectively of  70  or  80  million  pounds  of  water  raised  one  foot 
high  with  the  expenditure  of  1000  pounds  of  steam.  These  types 
of  engines  of  the  small  units  stated  should  give  a  station  duty 
more  than  double  that  of  the  type  of  engines  first  described. 

In  installations  of  large  units  the  test  duty  will  run  over  a 
hundred  million  pounds  of  water  one  foot  high  with  an  expenditure 
of  1000  pounds  of  steam,  and  the  station  duty  becomes  propor- 
tionately as  high. 

Duties  as  high  as  130  to  160  million  pounds  of  water  raised  one 
foot  high  with  the  expenditure  of  1000  pounds  of  steam  may  be 
obtained  from  double-  or  triple-expansion  fly-wheel  engines  in 
pumping  large  volumes  of  water  to  a  considerable  height.  Engines 
of  this  type  are  adapted  for  use  in  connection  with  the  water- 
works of  large  cities  which  depend  upon  the  constant  use  of  the 
pumps  for  their  water-service.  They  are  expensive  machines  and 
require  skilled  mechanics  as  attendants.  Very  high  station  duties 
may  be  maintained  with  this  type  of  engine  working  under 
favorable  conditions,  and  very  long  life  may  be  expected  of  massive, 
slow-moving,  and  self-contained  pumping-engines  of  this  type. 

The  centrifugal  or  turbine  pump  actuated  by  a  reciprocating  en- 
gine is  peculiarly  adapted  to  low-lift  work  because  of  the  cheapness 
with  which  such  machinery  can  be  installed  in  comparison  with 


200  WATER-SUPPLIES. 

economically  working  reciprocating  pumping-engines.  Installa- 
tions of  this  character  are  frequently  recommended  in  connection 
with  settling-basins  and  niters  and  numerous  other  uses  of  a 
similar  kind.  A  few  installations  are  to  be  found  of  high-lift 
turbine-pumps,  but  there  seems  thus  far  to  be  no  substantial 
encouragement  that  they  are  capable  of  accomplishing  heavy 
work  as  economically  as  the  higher  grades  of  the  reciprocating 
pumping-machinery.  Even  in  moderately  low-lift  pumping  a 
well-designed  reciprocating  pump  will  work  more  economically 
than  the  centrifugal  pump,  assuming  either  type  of  pump  to  be 
operated  by  an  equally  efficient  steam-engine.  The  only  element  of 
annual  expense  which  will  weigh  against  the  reciprocating  pump- 
ing-engine  and  in  favor  of  the  centrifugal  pumping-engine  is  the 
interest  on  the  cost  of  manufacture,  transportation,  and  installa- 
tion. When  this  element  of  charge,  taken  in  connection  with  the 
annual  cost  of  operation  and  maintenance  of  the  reciprocating  type 
of  machine,  exceeds  similar  expenses  in  the  aggregate  of  the  cen- 
trifugal type  of  machine,  the  latter  installation  becomes  the  cheaper. 
When  the  lift  is  very  low  and  very  large  volumes  of  water  are  to 
be  handled  periodically  the  centrifugal-pump  installation  becomes 
the  more  economical.  The  centrifugal  pump  as  ordinarily  manufac- 
tured is  of  comparatively  low  efficiency,  and,  so  far  as  we  may 
judge  from  the  few  reliable  tests  of  such  pumps,  the  efficiency  is 
more  often  below  than  above  50  per  cent,  and  sometimes  as  low 
as  35  per  cent.  Intelligent  design  and  careful  shop-work  are  neces- 
sary to  produce  an  efficiency  of  60  to  70  per  cent. 

The  centrifugal  or  turbine  pump  gives  its  best  efficiency 
when  running  at  a  constant  speed  and  delivering  water  against  a 
uniform  head  and  is  therefore  poorly  adapted  to  that  condition 
of  service  which  requires  occasional  change  from  a  reservoir 
delivery  to  a  direct-pressure  delivery. 

The  rotary  motion  of  this  class  of  pumping-machinery  pecu- 
liarly adapts  it  to  a  direct  connection  with  an  electric  motor 
wherever  occasion  requires  pumping  by  transmitted  power. 

A  pumping-engine  of  any  grade  does  its  best  work  when  moving 
constantly  at  its  rated  capacity  and  delivering  water  against  a 
steady  pressure,  as  when  delivering  water  into  a  reservoir.  But 
reservoir-pumping  warrants  the  installation  of  the  highest  grade 


PUMPING-ENGINES.  201 

of  pumping-machinery  only  when  the  volume  of  water-consump- 
tion is  sufficient  to  require  the  continuous  use  of  pumps  of  large 
capacity.  When  large-capacity  machinery  is  so  operated  under 
skilled  mechanical  supervision  it  should  give  the  highest  attainable 
station  duty. 

The  same  class  of  machinery  operated  under  direct -pressure  ser- 
vice gives  a  lower  station  duty  because  in  a  service  of  this  kind 
the  fluctuating  rate  of  consumption  produces  a  fluctuating  rate 
of  speed,  and  correspondingly  a  momentary  fluctuation  of  duty 
which  in  the  average  is  considerably  below  the  duty  of  the  machine 
moving  uniformly  at  its  best  speed  under  steady  reservoir  pressure. 

As  a  rule  it  does  not  pay  to  install  high-duty  pumping-engines 
in  localities  where  the  water-lift  is  light  and  the  daily  period 
of  service  short ;  besides  the  local  cost  of  fuel  is  to  a  considerable 
extent  an  influencing  factor.  Small  towns  very  properly  install 
comparatively  low-duty  engines  during  the  probationary  period 
and  gradually  increase  the  duty  of  future  installations  as  the 
consumption  and  hours  of  service  progressively  increase. 

The  life  of  a  pumping-engine  depends  upon  the  carefulness 
and  intelligence  with  which  it  is  operated  and  kept  in  repair, 
quite  as  much  as  upon  the  design  and  construction  for  the 
particular  work  which  it  is  required  to  perform  in  daily  practice. 
The  wear  and  tear,  or  in  other  words  the  cost  of  maintenance,  de- 
pends very  much  upon  the  simplicity  of  design  of  the  machine, 
perfection  of  workmanship,  rigidity  of  imporant  parts,  and  stability 
of  installation,  and  the  rate  of  deterioration  of  moving  parts  depends 
in  a  great  measure  upon  the  number  of  reversals  in  any  unit  of 
time.  That  is  to  say,  high-speed  operation  generally  contributes 
in  a  greater  degree  to  the  cost  of  maintenance  than  does  low-speed 
operation. 

The  mechanical  life  of  a  machine  which  is  under  good  attend- 
ance and  is  not  overworked  may  be  very  long,  but  its  actual  life 
depends  very  much  upon  the  rate  at  which  it  is  called  on  to 
work.  Whenever  its  capacity  becomes  exceeded  or  daily  require- 
ments of  work  reach  a  point  where  the  machine  of  itself  fails 
simply  because  of  incapacity,  its  usefulness  as  an  independent 
factor  becomes  impaired  although  mechanically  it  may  be 
altogether  reliable.  This  situation  can  be  met  by  the  installa- 


202  WATER-SUPPLIES. 

tion  of  larger  machinery,  but  it  does  not  necessarily  require  the 
complete  abandonment  of  the  older  machine,  which  may  yet  per- 
form important  and  satisfactory  service  as  a  reserve  machine. 

Instances  arise  where  the  actual  substitution  of  one  machine 
for  another  in  the  daily  service  produces  a  saving  in  station  ex- 
penses which  warrants  the  change  regardless  of  the  fact  that  the 
older  machine  may  be  thoroughly  reliable  mechanically,  but  the 
act  of  substitution  cannot  be  interpreted  as  reflecting  complete 
mechanical  deterioration  of  the  abandoned  machine,  so  long  as 
it  remains  a  part  of  the  station  equipment  and  can  be  used  in  a 
secondary  if  not  in  a  primary  capacity.  The  benefit  of  the  change 
is  to  be  found  directly  in  the  decreased  station  expenditure  result- 
ing from  the  use  of  the  more  economically  working  substitute  for 
the  heavy  daily  service.  The  complete  abandonment  of  the  older 
machine  as  a  part  of  the  station  equipment  will  seem  to  be  justified 
only  when  the  extra  expense  of  operating  and  maintaining  it  in  a 
subordinate  capacity,  plus  interest  on  the  investment  in  its  pur- 
chase and  installation,  is  considerably  greater  than  the  sum  of 
similar  charges  against  an  installation  of  a  higher  grade  but  more 
costly  machine  intended  for  work  in  a  similar  subordinate  capacity. 

The  basis  of  a  guaranteed  duty  for  some  specified  set  of  con- 
ditions is  the  proper  basis  for  the  purchase  of  pumping-machinery. 
But  the  basis  of  purchase  is  seldom  adopted  in  the  purchase  of 
the  small  direct-acting  pumping  units  installed  in  small  water- 
works, for  the  reason  that  the  volume  of  water  pumped  is  so  small 
and  the  daily  period  of  service  so  short  that  the  cost  of  the  fuel 
consumed  in  actual  pumping-service  is  small  in  comparison  with 
the  other  annual  station  expense;  frequently  the  saving  in  fuel 
resulting  from  the  use  of  a  more  efficient  type  of  pumping-machinery 
will  not  amount  to  the  interest  on  the  difference  in  cost  of  the  two 
installations. 

However,  as  the  volume  of  water  pumped  increases  and  the 
daily  period  of  service  lengthens,  the  need  of  a  higher  grade  of 
pumping-machinery  becomes  necessary  and  apparent,  and  natu- 
rally the  duty  basis  of  purchase  becomes  an  independent  and 
usually  a  controlling  consideration. 

The  penalty  for  non-fulfillment  of  the  duty  guarantee  some- 
times takes  the  form  of  a  provision  retaining  a  percentage  of  the 


PIMPING-ENGINES.  203 

purchase-price  until  a  proper  test  of  the  pumping-machinery  in- 
stalled shall  have  demonstrated  its  ability  and  capacity  to  give 
the  duty  guaranteed  of  it;  at  other  times  a  forfeit  is  demanded 
upon  the  basis  of  a  specified  sum  to  be  forfeited  for  each  one  mil- 
lion foot-pounds  of  duty  the  work  of  the  engine  falls  below  the 
guaranteed  duty.  In  this  regard  the  manufacturer  has  good 
reason  for  insisting  that  a  forfeiture  provision  of  the  latter  char- 
acter should  be  balanced  by  a  premium  clause  offering  some  speci- 
fied bonus  for  each  one  million  foot-pounds  of  work  the  engine 
proves  itself  capable  of  performing  in  excess  of  the  guaranteed 
duty.  Unless  there  is  some  balancing  provision  of  this  character 
the  forfeiture  clause  of  itself  may  result  in  higher  bids  than  would 
otherwise  be  the  case. 

Such  provisions,  however,  are  customary,  as  a  rule,  with  large 
and  high-class  pumping-machinery  only. 


CHAPTER  IV. 

IMPOUNDED  SUPPLIES. 

THE  flow  of  rivers  and  streams,  the  waters  of  which  are  of 
sufficient  purity  for  use  without  purification,  is  usually  less  during 
certain  periods  of  a  year  than  the  demands  for  water-supply  pur- 
poses. To  insure  an  adequate  supply  during  periods  of  low  stream- 
flow,  the  water  of  freshets  and  flows  in  excess  of  the  consumption 
by  the  works  is  stored  in  impounding  or  storage  reservoirs.  These 
may  be  natural  lakes  and  ponds,  or  artificial  reservoirs  formed  by 
the  construction  of  dams  across  the  valleys  through  which  the 
streams  flow.  In  many  instances  artificial  reservoirs  are  repro- 
ductions wholly  or  in  part  of  ancient  lakes. 

The  water  from  a  storage  reservoir  is  to  be  preferred  to  that 
taken  directly  from  a  stream,  inasmuch  as  the  quality  of  a  surface- 
water  is  improved  by  storage  in  a  reservoir  of  sufficient  capacity 
which  has  been  properly  prepared  for  service.  The  effects  of  pol- 
lution by  organic  impurities  are  more  marked  in  instances  where 
water  is  taken  directly  from  a  stream  than  where  the  supply  is 
obtained  from  a  large  storage  reservoir,  since  the  period  which 
elapses  from  the  time  of  contamination  to  that  of  consumption 
in  the  first  instance  is  usually  insufficient  to  result  in  the  elimina- 
tion of  the  germs  of  typhoid  fever  and  other  intestinal  diseases. 
The  fact  that  epidemics  of  typhoid  fever  have  been  due  to  polluted 
surface-water  supplies  taken  directly  from  streams  is  at  present 
well  established,  and  no  community  supplied  in  this  manner  is 
safe  from  these  epidemics  when  the  catchment  area  of  the  stream 
is  inhabited. 

In  all  probability  pathogenic  organisms  do  not  multiply  in 
water-supplies,  and  experiments  made  by  biologists  indicate  that 

204 


IMPOUNDED  SUPPLIES. 


205 


these  organisms  do  not  retain  their  vitality  longer  than  one 
month  in  the  water  of  a  reservoir.  Consequently  storage  reservoirs 
act  as  safeguards  against  epidemics  of  intestinal  diseases. 

The  period  of  quiescence  which  the  water  of  a  large  reservoir 
undergoes  is  beneficial,  since  the  turbidity  of  the  entering  water 
during  freshet  flows  in  particular  is  considerably  if  not  entirely 
reduced  as  a  result  of  sedimentation.  The  color  of  a  water  is  also 
reduced  by  storage  in  consequence  of  the  bleaching  action  of  sun- 
light. This  effect  is  shown  by  the  following  table.* 

TABLE  SHOWING  THE  EFFECT  OF  LONG  STORAGE  UPON  THE  COLOR  OF  WATER. 


Average 

Estimated 

Percentage 

time  re- 

average 

Locality. 

of  water- 
shed above 

quired  to 
fill  the 

Color  at 
main  inlet. 

color  of 
all  water 

Color  at 
outlet. 

Change. 

inlet. 

reservoir, 

entering 

months. 

reservoir. 

Boston, 

Reservoir  3  .... 

79 

i-3 

I  .OO 

0.86 

0.82 

—  o    04 

Reservoir  2  .... 

97 

0.4 

I.  10 

1.07 

0.98 

—  0.09 

Lake  Cochituate 

40 

8-5 

0.86 

0.58 

0.25 

—0-33 

Reservoir  4  .... 

84 

7-5 

i  .40 

1.27 

0.72 

—  °-55 

(Ashland) 

Brockton     Reser- 

voir   

82 

3-4 

2.24 

1.87 

0.89 

—  0.98 

It  should  be  noted  that  the  color  of  a  stored  water  is  not  materially 
reduced  unless  the  period  of  storage  is  about  eight  months. 

The  beneficial  effect  of  long  storage  upon  the  color  of  a  water 
is,  however,  materially  affected  by  the  condition  of  the  reservoir 
bottom.  When  the  reservoir  site  has  been  carefully  prepared  by 
the  removal  of  organic  matter  and  the  entering  water  contains  little 
or  no  matter  in  suspension  the  best  results  are  secured.  On  the 
contrary  when  the  bottom  of  the  reservoir  is  muddy  the  color  of 
the  bottom  layers  in  deep  reservoirs  is  increased  during  the  stagna- 
tion periods  which  are  common  to  reservoirs  of  a  depth  greater 
than  twenty  feet.  The  following  tables  illustrate  the  effect  of 
organic  deposits  in  a  reservoir  upon  the  color  of  the  contained 
water,  f 

*  Stearns  and  Drown.  ' '  Discussion  of  Special  Topics  relating  to  the 
Quality  of  Public  Water-supplies."  Report  of  Mass.  State  Board  of 
Health  on  Water-supply  and  Sewerage,  Vol.  I.  1889. 

t  Boston  Water  Reports,  1892,  pp.  96,  97. 


206  WATER-SUPPLIES. 

COLOR  OP  WATER  IN  LAKE  COCHITUATE  AT  DIFFERENT  DEPTHS. 

(Depth  60-65  feet.) 

1890.                                                 Surface.  Mid-depth.               Bottom. 

August  5 o.io  020                    0.80 

"  II O.IO  O.20  2.8O 

19 0.15  0.30  3.80 

26 0.15  0.30  2.80 

September  3 o.io  0.30  2.30 

"           9 o.io  0.30  2.60 

COLOR  OF  WATER  IN  BASIN  4  (ASHLAND  RESERVOIR)  OF  BOSTON  WATER- 
WORKS AT  DIFFERENT  DEPTHS. 

(Depth  30-35  feet.) 
1890.  Surface.  Mid-depth.  Bottom. 

Augusts 0.50  0.50  0.50 

13 0.35  0.50  0.60 

"        18 0.40  0,50  0.80 

26 0.50  0.45  0.80 

September  3 0.40  0.40  0.70 

9 0.40  0.45  0.70 

The  Ashland  Reservoir  was  prepared  by  the  removal  of  all  the 
loam  from  the  site,  and  at  the  time  the  samples  were  taken  the 
bottom  was  composed  of  clean  material. 

During  the  circulation  periods  the  water  of  the  lower  layers 
of  deep  lakes  and  reservoirs  is  mingled  with  the  nearly  colorless 
water  near  the  surface,  thus  changing  the  color  of  the  entire  mass. 
Not  only  is  the  color  of  the  water  affected  in  the  manner  indicated, 
but  the  quality  of  a  water  obtained  from  a  reservoir  containing 
organic  deposits  in  contact  with  the  water  is  injured  in  other  ways. 
The  water  of  the  bottom  layers  coming  in  contact  with  organic 
matter  during  the  period  of  stagnation  is  deprived  of  its  free  oxygen 
and  becomes  charged  with  organic  matter  in  various  stages  of 
decomposition.  This  foul  water  when  mingled  with  the  upper 
layers  gives  rise  to  disagreeable  tastes  and  odors  due  to  the  matter 
in  solution  and  suspension,  or  to  the  organisms  which  derive  their 
food-material  from  this  matter. 

"The  effect  of  the  character  of  the  reservoir  upon  the  stored 
water  is  best  indicated  in  a  chemical  analysis  by  the  free  ammonia, 
which  is  a  product  of  decomposition,  and  the  albuminoid  ammonia, 
particularly  the  suspended  portion  of  the  latter,  which  indicates  the 
abundance  of  organisms  and  other  suspended  organic  matter 


IMPOUNDED  SUPPLIES. 


207 


contained  in  the  water."  *     Analyses  of  water  from  two  cleaned 
and  three  uncleaned  reservoirs  in  Massachusetts  are  given  below. 


Date 

Number 

Ammonia 

Reservoir. 

Con  d.  it  ion  • 

Date 

of 
collect- 

ot 
months 

Albuminoid. 

of 
filling. 

ing 
sample. 

between 
dates. 

Free. 

Total. 

Dis- 
solved. 

Sus- 
pended. 

r 

Cleaned 

April 

Aug. 

Boston,  Reservoir  i 

1886 

1887 

16 

o  .0005 

0.0339 

— 

— 

No.  4  (Ashland)  1 

" 

•• 

Aug. 

I 

1888 

38 

0  .  000  3 

0.0386 

0.0354 

0.0033 

Cambridge,  S  t  o  ny 
Brook  Reservoir  . 

.. 

Aug. 

Aug. 

1887 

1888 

13 

O.OOIO 

0.0388 

0.0234 

0.0054 

Quincy  Reservoir 

Uncleaned 

Dec. 

Aug. 

1888 

1889 

8 

o.oaoo 

0.0466 

0.0386 

0.0080 

•i              •• 

•• 

44 

Aug. 

1  890 

30 

O.OIIO 

0.0360 

0.0373 

0.0088 

Lynn  ,  Glen  Lewis  Pd. 

Uncleaned 

Dec. 

Aug. 

1889 

1890 

8 

0.0633 

o  .  0903 

0.0746 

0.0156 

Lynn,  Walden  Pond 

•• 

Dec 

Aug. 

1889 

1890 

8 

0.0576 

o  .  0746 

0.0560 

0.0186 

The  reduction  of  color  due  to  long  storage  and  the  effect  of 
cleaning  a  reservoir  site  is  shown  by  Figs.  33  and  34.  The 
changes  during  a  year  in  the  color  of  the  influent  streams,  the 
surface-water,  and  the  water  at  the  bottom  of  two  reservoirs  in 
Massachusetts — a  clean  reservoir  (Ashland)  and  an  uncleaned 
reservoir  (Lake  Cochituate) — are  indicated  on  these  diagrams. 

The  micro-organisms  producing  disagreeable  odors  in  water- 
supplies  are  not  usually  present  in  flowing  streams,  but  find  the 
most  favorable  conditions  for  their  growth  in  the  quiet  waters  of 
lakes  and  reservoirs.  The  extent  of  their  development  depends 
in  large  measure  upon  the  available  food-supply,  and  clean  water 
stored  in  a  clean  reservoir  presents  the  least  favorable  conditions 
for  their  existence.  The  nitrogenous  matter  contained  in  the 
water  of  the  entering  streams  or  derived  from  the  bottom  and 
sides  of  the  reservoir  itself  affords  means  for  their  growth  often 
in  considerable  numbers.  Even  if  the  reservoir  site  be  carefully 
prepared,  the  water  entering  the  reservoir  from  an  inhabited 
catchment  area,  although  perhaps  thoroughly  purified,  usually 
contains  nitrogenous  material,  and  a  storage  reservoir  is  rarely 
free  at  all  times  from  micro-organisms. 

The  experience  in  Massachusetts  has  been  that  trouble  due  to 
taste  and  odors  of  water-supplies  is  greatly  reduced  by  the  removal 
of  material  containing  more  than  four  per  cent  organic  matter 


*  Report  of  Mass.  State  Board  of  Health,  1890,  p.  33. 


208 


WATER-SUPPLIES. 


from  the  reservoir  sites,  or  the  covering  with  clean  sand  and  gravel 
of  deposits  too  deep  to  be  economically  removed.  Shallow  margins 
are  avoided  either  by  excavating  material  until  a  sufficient  depth 


•3 


1    I 


Color  of  Water  in  Ashland  Reservoir 
1903 

FIG.  33. 


is  secured,  or  filling  along  the  shores  to  make  clean  beaches.  The 
excessive  growth  of  grass  and  weeds  along  the  shores  during  periods 
of  low  water  is  thus  avoided. 


IMPOUNDED  SUPPLIES. 


209 


In  addition  the  quality  of  the  water  entering  a  prepared  reser- 
voir is  improved  by  measures  taken  to  drain  swamps  upon  the 
catchment  area,  to  provide  for  the  interception  of  surface-  and 
ground-water  before  it  reaches  these  swamps  and  its  conveyance 
to  the  reservoir,  and  for  the  disposal  or  treatment  of  sewage  from 
buildings  upon  the  area  of  catchment. 


10 


Color  of  Water  in  Lake  Cochituate 
1903 

FiG.  34. 

In  the  case  of  natural  lakes  or  ponds  which  are  subject  to 
periods  of  stagnation  and  circulation,  the  effect  of  these  occurrences 
upon  the  quality  of  the  water  is  usually  not  so  marked  as  has 
been  indicated  with  respect  to  artificial  reservoirs.  Indeed,  the 
view  is  often  advanced  that  the  stripping  of  a  reservoir  site  is 
an  item  of  unnecessary  expense  inasmuch  as  in  course  of  time 
through  the  dissolving  action  of  the  water  the  bottom  of  a  reser- 
voir will  approach  a  condition  similar  to  that  of  a  natural  lake. 


210 


WATER-SUPPLIES. 


The  length  of  time  required  to  accomplish  this  end  is,  however, 
very  uncertain,  and  unless  the  benefits  of  stripping  are  liable  to 
be  impaired  by  deposits  washed  into  the  reservoir  by  freshets  it  is 
considered  advisable  to  expend  funds  for  the  purpose  of  removing 
objectionable  material  from  the  bottom  and  sides  of  an  impound- 
ing reservoir. 

An  objection  to  a  supply  of  water  from  a  shallow  impounding 
reservoir  is  based  upon  the  comparatively  high  temperature  of  the 
water  during  the  summer  months.  The  temperature  of  the  upper 


80 

TO 

^60 

.d 

I 

I* 

1 
J?4° 

30 
20 

!  I  1  1  I  1  !  4  fill 

/ 

"^s 

^ 

/ 

^ 

\ 

i 

/ 

*•     •>; 

\ 

\ 

^ 

/- 

^' 

*^ot 

toSL. 

_\ 

\ 

^.^^ 

'/ 

\ 

Temperature  of  Water  in  Lake  Cochituate 
FIG.  35. 

layers  is  favorable  to  the  growths  of  objectionable  organisms,  and 
unless  the  reservoir  is  clean,  water  cannot  be  advantageously 
drawn  from  the  cooler  layers  near  the  bottom  even  when  the 
reservoir  is  deep.  The  warm  water  Irom  a  shallow  reservoir  is  not 
looked  upon  with  favor  by  consumers,  as  the  water,  even  if  un- 
affected by  organisms  producing  tastes  and  odors,  is  not  very 
palatable  unless  cooled.  Owing  to  the  evaporation  losses  from 
large  areas  of  water-surface  and  the  high  temperature  of  the 
water  of  shallow  reservoirs  during  warm  weather,  impounding 
reservoirs  should  be  constructed  of  considerable  depth. 

The  capacity  of  an  impounding  reservoir  in  any  given  instance 


IMPOUNDED  SUPPLIES.  21 1 

is  dependent  upon  local  conditions,  the  amount  of  storage  to  be 
provided  being  computed  from  actual  or  estimated  figures  for 
yield  and  consumption.  The  yield  used  in  these  computations 
should  not  be  the  average  yield  of  the  catchment  area  under 
consideration,  but  the  yield  during  a  dry  year  or  a  succession  of 
dry  years.  In  the  absence  of  definite  information  regarding  the 
rainfall  on  or  run-off  from  a  catchment  area,  comparisons  are 
made  with  areas  for  which  suitable  records  are  available.  In  mak- 
ing these  comparisons,  allowances  are  made  for  differences  due  to 
topographical  and  geological  conditions  affecting  the  yield  of  the 
respective  areas.  Such  conditions  are  the  relative  altitude  of  the 
areas,  distance  from  the  sea  or  large  inland  lakes,  and  the  proximity 
of  mountain  ranges,  etc.,  as  affecting  the  rainfall;  the  size  of  the 
catchment  area,  character  of  vegetation  upon  the  area,  extent 
of  forests,  general  slope  of  surface,  amount  of  impervious  surface, 
character  of  the  material  composing  the  different  strata,  tempera- 
ture of  the  air,  etc.,  as  affecting  yield.  Furthermore,  the  losses 
by  evaporation  from  the  water  surfaces  in  the  area,  and  the  losses 
due  to  percolation  or  seepage  from  the  reservoir  and  the  area 
itself  are  considered.  Tables  or  diagrams  are  prepared  giving  the 
actual  or  estimated  rainfall,  run-off,  consumption,  evaporation, 
and  other  losses  by  months  from  which  the  amount  of  storage 
required  is  computed. 

The  danger  of  using  average  values  for  rainfall  and  yield  in 
storage  computations  is  shown  by  the  table  of  statistics  for  the 
Sudbury  catchment  area.  The  average  results  obtained  from  1875 
to  1904,  figures  for  the  two  years  in  which  the  yield  was  the  lowest 
recorded  and  figures  for  the  year  in  which  the  yield  for  six  months 
was  a  minimum,  are  given  in  this  table.  The  fluctuations  during 
the  period  covered  by  the  observations  are  shown  in  Fig.  36. 

The  matter  of  storage  on  the  Sudbury  area  has  been  carefully 
studied  by  the  engineers  connected  with  the  Boston  works,  and 
the  results  of  these  studies  are  contained  in  Mr.  Fitzgerald's  paper 
on  "  Rainfall,  Flow  of  Streams,  and  Storage."  *  The  diagram  of 
storage  capacity  is  prepared  from  that  given  in  the  paper  mentioned 
and  is  applicable  to  catchment  areas  in  New  England  comparable 

*  Trans.  Am.  Soc.  C.  E.,  Vol.  XXVII. 


212 


WATER-SUPPLIES. 


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IMPOUNDED  SUPPLIES. 


213 


to  the  Sudbury.  Results^  obtained  by  the  use  of  this  diagram  are 
modified  by  the  statement  that  "  as  it  is  undesirable  to  keep 
the  water  below  high  water  for  more  than  two  years  in  sue- 


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FIG.  36.  —  Diagram  of  Yield  of  the  Sudbury  River  Catchment  Area. 

Catchment  area:  1875-1878=  77.764  square  miles 
1879-1880=78.238     '• 
1881-1905=  75.2 

Per  cent  of  water-surface:  1875-1878=  1.9% 
Increased  in  1879  to  3.0% 
"  1885  "  3.4% 
"  1894  "  3.9% 


cession,  ...  it  is  impracticable  to  secure  more  than  about  750,- 
ooo  gallons  daily  from  i  square  mile  of  watershed  containing  10 
per  cent  of  water-surface."*  To  secure  this  supply  a  storage 

*  Trans.  Am.  Soc.  C.   E.,  Vol.  XXVII,  p.   268.     ("Rainfall,   Flow  of 
Streams,  and  Storage."     Fitzgerald.) 


214 


WATER-SUPPLIES. 


capacity  of  about  222  million  gallons  per  square  mile  is  required. 
This  is  equivalent  to  about  56  per  cent  of  the  average  annual  yield. 


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The  effect  of  varying  percentages  of  water-surface  upon  the 
area  of  catchment  is  clearly  shown  by  the  diagram,  and  the  extent 
of  water-surface  should  be  kept  below  10  per  cent  of  this  area 
whenever  practicable.  In  the  case  of  natural  lakes  and  ponds  in 


IMPOUNDED  SUPPLIES. 


2*5 


10     20 


Sole  of  Feet 
30    40     50    60    70     80    90    100 


X:.'v-:-ff     E-15.8 


MAXIMUM  SECTION  OF  NEW  C.ROTON  DAM. 
FIG.  38. 


2 1 6  WA  TER-SUPPLIES. 

New  England  where  the  proportion  of  water-surface  is  compara- 
tively large,  the  available  storage  may  be  from  one  to  one  and 
one-half  times  the  average  annual  yield. 

Dams  or  embankments  are  a  feature  of  all  artificial  reservoirs, 
and  often  the  selection  of  a  reservoir  site  depends  upon  the  practi- 
cability and  cost  of  the  necessary  structures  to  retain  the  water 
therein.  Provision  is  also  made  for  the  disposal  of  the  water 
from  freshets  which  cannot  at  all  times  be  stored.  Unless  the 
main  dam  is  designed  to  pass  water,  which  is  not  usually  the  case 
with  any  but  very  low  structures,  masonry  spillways  or  waste- 
weirs  should  be  constructed  of  sufficient  capacity  to  waste  the 
water  from  the  maximum  known,  or  anticipated,  flood  without 
danger  of  overtopping  the  dam.  The  site  of  the  spillway  depends 
upon  the  topography  of  the  valley  in  which  the  reservoir  is  situated 
and  the  proximity  of  the  bed-rock  to  the  surface.  When  the 
dam  is  of  considerable  height  the  spillway  is  located  at  one  side 
of  the  valley  if  possible,  with  its  crest  from  six  to  twenty  feet 
below  the  top  of  the  main  structure. 

Dams  of  a  height  exceeding  about  seventy-five  feet,  when  built 
in  connection  with  reservoirs  of  considerable  extent,  are  usually 
constructed  of  masonry.  The  masonry  may  be  rubble,  concrete, 
or  cyclopean  faced  with  ashlar  or  concrete  blocks  to  make  a  neat 
finish.  The  foundations  of  high  masonry  dams  are  carried  to 
sound  bed-rock.  Fig.  38  shows  a  typical  cross-section  of  a 
modern  high  masonry  dam,  the  New  Croton,  which  is  the 
highest  yet  constructed. 

Rock-fill  dams  have  been  used  in  some  instances  in  the  West 
where  cement  could  not  be  economically  procured.  Dams  of  this 
class  are  made  more  or  less  water-tight  by  a  facing  or  core  of  con- 
crete, timber,  or  protected  steel  plates. 

Earth  is  largely  used  in  the  construction  of  dams  and  embank- 
ments, gravelly  earth  being  considered  the  best  material  for  this 
purpose.  Earth  dams  are,  or  should  be,  provided  with  a  core-wall 
of  masonry  unless  the  bank  is  of  unusual  thickness  and  in  no  danger 
of  ever  being  overtopped.  The  core-wall  is  usually  of  concrete  and 
is  carried  to  bed-rock  on  the  bottom  and  sides  of  the  valley  when 
this  can  be  done  with  economy.  Otherwise  the  core-wall  is  founded 
on  hard-pan  or  other  impervious  material.  Sheet-piling  has  been 


IMPOUNDED  SUPPLIES.  217 

used  in  some  instances  beneath  the  core-wall  when  the  rock  was 
at  a  considerable  depth. 


FIG.  39. — Cross-section  of  Earth  Dam. 

Earth  dams  of  ordinary  height  vary  in  thickness  from  12  to 
30  feet  at  the  top  and  have  side  slopes  from  i  J  :  i  to  3:1. 
The  top  is  usually  from  6  to  10  feet  above  high-water  level.  The 
slopes  on  the  water  side  are  paved  with  stone  to  the  height  reached 
by  waves,  and  the  down-stream  slopes  are  sodded  or  faced  with 
loam  and  sown  to  grass. 

When  the  height  of  the  embankment  exceeds  30  to  40  feet 
a  berm  is  generally  built  at  about  mid-height  on  the  water 
side  to  guard  against  the  slipping  of  the  stone  paving.  A  similar 
berm  is  also  placed  on  the  down-stream  side  to  prevent  washing 
of  the  material  by  rains.  Below  the  berm  on  the  water  side  the 
slope  is  often  riprapped  with  heavy  stones  as  a  substitute  for  the 
paving. 

The  outlet-pipes  from  the  reservoir  and  the  controlling-valves 
are  placed  in  gate-towers  or  chambers  which  are  usually  built  in 
connection  with  the  masonry  portion  of  the  dam  or,  in  the  case  of 
earth  embankments,  as  independent  structures. 


PART  II. 
MAINTENANCE  AND   OPERATION. 


CHAPTER  I. 

PLANS  AND  RECORDS. 

AN  important  requisite  for  the  successful  management  of  a 
system  of  water-works  is  a  complete  set  of  plans  and  records. 
These  should  be  accurate,  should  be  kept  up  to  date,  and  should 
admit  of  ready  interpretation.  Dependence  should  not  be  placed 
upon  scattered  and  fragmentary  notes  in  numerous  field  and 
office  note-books,  nor  upon  the  memory  of  any  person  or  persons 
having  charge  of,  or  connected  with,  any  portion  of  the  works. 
The  value  of  such  plans  and  records  may  not  be  apparent  at  the 
outset,  but  the  changes  which  inevitably  take  place  through  the 
growth  of  a  community,  with  the  resulting  obliteration  of  old 
landmarks,  the  relocation  of  street-lines,  the  changes  in  the  per- 
sonnel of  the  department,  and  so  on,  very  soon  indicate  that  funds 
expended  for  the  proper  preservation  of  data  have  been  expended 
wisely. 

Construction  Plans. 

In  the  case  of  surface-water  supplies,  maps  or  plans  should 
be  prepared,  upon  which  are  indicated  the  source  of  supply,  the 
catchment  area,  all  water-surfaces,  buildings,  dams,  and  intakes. 
These  plans  or  notes  thereon  should  furnish  information  regarding 

218 


PL/INS  AND  RECORDS.  219 

the  size  of  the  catchment  ^area,  and  the  extent  of  water-surface 
at  varying  elevations  for  use  in  making  computations  of  yield. 

Detailed  plans  of  all  pipes  and  appurtenances  in,  and  in  the 
vicinity  of,  gate-chambers,  pumping-stations,  filtration-plants, 
reservoirs,  and  stand-pipes  are  to  be  desired. 

Accurate  plans  of  the  distribution  system  should  be  prepared 
from  surveys  made,  or  based  upon  measurements  taken,  during 
the  work  of  construction.  These  plans  may  vary  in  character  from 
the  carefully  drawn  atlas  sheets  on  a  scale  of  forty  or  fifty  feet 
to  the  inch,  upon  which  are  indicated  the  main  pipes,  valves, 
hydrants,  plugged  branches,  service  connections,  street-  and  curb- 
lines,  and  all  buildings,  to  the  single  sheet  upon  which  main  pipes, 
valves,  hydrants,  and  street-lines  alone  are  shown  on  a  scale  which 
will  admit  of  the  plotting  of  the  distribution  system  upon  a  single 
plan,  as  the  funds  available  for  this  purpose  may  determine. 

The  record  plans  should  preferably  be  made  upon  heavy 
paper  mounted  on  linen,  as  plans  on  tracing-cloth  are  not  very 
durable  and  in  addition  cannot  be  accurately  scaled  owing  to 
the  shrinkage  of  the  material.  Copies  of  the  plans  in  the  form 
of  tracings  or  blue-prints  made  therefrom  may,  however,  be  of 
service.  The  several  sizes  of  pipe  may  be  indicated  upon  the 
plans  by  inks  of  different  colors,  valves  by  short  heavy  black 
lines  at  right  angles  to  the  pipe-line,  and  hydrants  by  small  circles. 
In  suburban  localities  where  street-lines  are  not  marked  by  monu- 
ments, or  are  otherwise  not  plainly  defined,  the  travelled  way  may 
be  shown  to  advantage  by  light  dotted  lines. 

A  skeleton  plan  of  the  entire  distribution  system,  either  drawn 
to  scale  or  carefully  sketched,  with  the  main  valves  indicated  will 
be  found  useful  for  many  purposes,  especially  in  connection  with 
a  valve-location  book. 

In  order  that  the  valves  on  street-mains  may  be  quickly  located 
in  time  of  need,  a  valve-location  book  is  indispensable.  .Where 
valves  are  set  on  the  street-lines,  tie  locations  may  not  be  necessary 
when  the  distance  of  the  valve  from  the  line  of  the  side  street  is 
known  and  both  street-lines  well  defined,  but  usually  locations 
by  ties  to  permanent  objects  are  advisable.  A  sketch  of  the 
immediate  vicinity  of  the  valve  should  be  made,  and  measure- 
ments taken  to  the  box-cover  from  the  corners  of  adjacent  build- 


22O 


MAINTENANCE  AND  OPERATION. 


ings,  trees,  hydrants,  light-poles,  etc.  At  least  three  ties  should 
be  taken  from  objects,  as  noted  above,  which  are  not  likely  to  be 
covered  by  snow,  the  distances  measured  being  preferably  such  as 
may  be  made  within  the  limits  of  a  fifty-foot  tape.  Copies  of 
the  sketches  should  be  made  upon  tracing-cloth  and  the  measure- 
ments with  the  points  from  which  they  are  to  be  taken  clearly 
indicated.  Blue-print  sets  of  valve  locations  can  then  be  bound 
in  book  form  for  convenient  use.  The  size  of  the  sheets  should 
admit  of  the  carrying  of  the  book  in  the  pocket,  sheets  four  by 


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FIG.  40. — Sketch  of  Location  of  Main  Valve. 

six  inches  being  suitable  for  the  purpose.  In  cities  a  departure 
from  the  method  of  measurements  outlined  may  be  made  by 
marking  points  at  equal  distances  from  the  valve-box  by  bolts  in, 
or  circles  marked  in  paint  on,  adjacent  buildings. 

Similar  tie-locations  may  be  made  of  plugged  branches  with  the 
addition,  of  notes  indicating  the  distance  of  the  branch  from  the 
nearest  valve  or  hydrant  branch. 

Since  service-pipes  as  a  general  rule  are  laid  at  right  angles  to 
the  axis  of  the  street,  the  curb-cock  alone  may  be  located  by 
measurements  from  the  corners  of  the  building  to  which  the  pipe 
is  laid  or  from  other  convenient  objects.  The  diagrams  of  the 
services  and  the  ties  to  the  service-boxes  may  be  made  upon  cards 


PLANS  AND  RECORDS. 


221 


which  are  filed  alphabetically,  according  to  the  name  of  the  property 
owner  or  occupant  of  the  premises,  or  by  streets  and  numbers,  at 
the  option  of  the  official  in  charge  of  the  work.  The  corporation 
cock  or  tap  may  be  located  by  similar  measurements  if  desired, 
or  both  curb  and  corporation  -cocks  may,  in  the  case  of  isolated 
buildings,  be  located  by  distances  along,  and  offsets  from,  the 
line  of  the  building  produced.  This  latter  method  of  location, 
however,  possesses  no  advantages  over  that  first  mentioned,  and 


\ 


FIG.  41. — Diagram  of  Service  Connection. 

relocations  cannot  be  made  as  accurately  as  by  the  use  of  measure- 
ments which  intersect  at  a  point. 


Construction  Records. 

The  plans  of  a  system  should  be  supplemented  by  records  kept 
in  specially  designed  books,  on  sheets  preserved  in  loose-leaf 
binders,  or  by  the  card  system.  The  first  method  is  preferable 
for  the  preservation  of  data  regarding  street  mains,  valves  and 
hydrants,  and  the  second  or  third  in  the  case  of  service  connec- 
tions, particularly  when  the  service  application  and  data  are 
entered  on  a  single  form.  In  addition  to  the  statistics  of  original 
construction,  information  respecting  alterations,  renewals,  and 
discontinuances  should  be  recorded. 


222  MAINTENANCE  AND   OPERATION. 

The  record-books  may  be  arranged  in  such  manner  that  informa- 
tion concerning  the  separate  items  may  be  placed  on  a  horizontal 
line;  the  data  being  entered  under  appropriate  headings  printed 
above  vertical  columns  covering  two  opposite  pages  of  the  book, 
or  one  page  if  an  oblong  book  is  used.  The  following  headings 
are  suggested  for  main-pipe,  valve,  and  hydrant  records: 

Main  Pipes:  Street;  Location;  Length  and  size  of  main 
(separate  columns  being  used  for  the  several  diameters  of  pipe 
used) ;  Distance  from  street-line;  Material;  Number  of  valves; 
Number  of  hydrants;  Length  and  size  of  hydrant  branches; 
Length  and  size  of  blow-off  branches;  Cost — pipe,  specials, 
valves,  valve-boxes,  hydrants,  lead  and  yarn,  labor,  teaming; 
Date  of  completion,  etc. 

Valves:  Street,  Location;  Size  (separate  columns  being 
used  for  the  several  sizes);  Type  of  valve;  Maker;  Turn  to 
open,  etc. 

Hydrants:  Street;  Location;  Size  of  main;  Length  and  size 
of  branch;  Number  and  kind  of  nozzles;  Type;  Maker;  Turn 
to  open,  etc. 

The  service  records  may  be  entered  on  printed  sheets  or  cards, 
the  service  application  and  data  appearing  on  one  side  of  the  form, 
the  reverse  being  used  for  the  diagram.  These  records  should 
furnish  information  upon  the  following  points:  Owner  and  Occu- 
pant of  Premises;  Street  and  Number;  Material  of  service-pipe; 
Diameter;  Length — main  to  curb-cock,  curb-cock  to  street-line, 
street-line  to  stop  and  waste;  Total  length;  Number  and  size  of 
taps;  Date  of  completion;  Cost — corporation-cock,  stop-cocks, 
service-box,  pipe,  labor,  teaming,  etc.  The  items  of  cost  may  be 
divided  in  order  that  the  respective  costs  within  the  limits  of 
the  street  and  in  private  property  may  be  ascertained  in  cases 
where  bills  are  rendered  the  property  owner  based  upon  actual 
expenditures  for  construction  outside  the  limits  of  the  street. 

A  specimen  service  application  and  record  is  shown  on  the 
following  page.  The  sheets  are  8  xioj  inches  in  size  and  are  filed 
in  loose-leaf  binders. 


PLANS  AND  RECORDS.  223 

TOWN  OF  CONCORD:    WATER  DEPARTMENT. 
Service  A  pplication . 

SERVICE  No 

CONCORD,  MASS 

To  the  Water  and  Sewer  Commissioners: 

The  undersigned  hereby  applies  for  a  supply  of  water  for 

the  premises  on Street,  owned  by 

and  occupied  by as  a and 

hereby  agree  to  conform  to  all  rules  and  regulations  now  or  to  be 

established  by  the  Commissioners. 

Applicant 

RECORD  OF  SERVICE. 
COST  WITHIN  STREET.  COST  WITHIN  PRIVATE  PROPERTY. 

Foreman  $ Foreman  $ 

Labor  Labor  

Team  Team  

....ft in pipe@       .  .  .  .ft  .  .  .  .in  .  .  .  .pipe  @      

Stop  and  Waste  Cock     Stop  and  Waste  Cock    

....  Corporation  Cock  

....  Service  Box  

Supervision  and  Use  of 

Tools  

Total  Total  $ .  . 


DIAGRAM  OF  SERVICE. 

Kind  of  Pipe  

Size  of  Pipe  

Main  to  Stop  

Stop  to  Line  

Line  to  Stop  and  Waste        

Total  Length  

Number  of  Taps 

Service  Completed  

Bill  Rendered  

Bill  Paid  

Remarks 

Maintenance  Records. 

Whenever  possible,  data  with  regard  to  the  yield  of  catchment 
areas  from  which  surface-water  supplies  are  obtained  should  be 
systematically  collected  and  recorded.  Observations  of  the  pre- 
cipitation at  one  or  more  points  on  the  area,  of  the  elevations 
of  the  water-surfaces  of  ponds,  lakes,  or  impounding  reservoirs  on 
the  area  of  catchment,  of  the  quantities  of  water  drawn  from  the 


224 


MAINTENANCE  AND   OPERATION. 


area  for  use  in  the  works,  and  of  the  amount  flowing  off  in  streams 
are  necessary  for  this  purpose. 

The  measurements  of  precipitation  should  be  made  with  a 
standard  gage.  The  instruments  adopted  by  the  U.  S.  Weather 
Bureau  are  described  and  directions  for  their  use  given  in  circulars 
published  by  that  Bureau.  (Measurement  of  Precipitation,  U.  S. 
Dept.  of  Agriculture,  Weather  Bureau,  1903;  Instructions  to 
Observers,  U.  S.  Dept.  of  Agriculture,  Weather  Bureau,  1903.) 

The  standard  gage  of  the  Weather  Bureau  is  shown  by  the 
accompanying  illustration.  This  gage  consists  of  a  receiver  (A) 
which  is  8  inches  in  diameter  inside,  a  measuring- tube  (C)  of  such 


FRONT  VIEW 


VERTICAL  SECTION 


^    a 

VAX 

1 

^n^ 

d 

B 

7* 

d 

B 

c 

HORIZONTALjSFCTION  E-F 

B 


Scale  of  Inches 


10  11  12  13  14  15  10  17  18  19  20  21  22  23  24 


FIG.  42. — Standard  Rain  Gage. 

diameter  that  the  depth  of  rainfall  collected  is  magnified  ten  times, 
a  graduated  measuring-stick  and  an  overflow  attachment  (B),  in 
which  rainfall  in  excess  of  the  capacity  of  the  measuring-tube 
may  be  collected.  Rainfall  is  measured  in  inches  and  decimals  of 
an  inch,  and  precipitation  in  the  form  of  snow  is  recorded  in  equiva- 
lent inches  of  rainfall.  Snowfall  is  collected  in  the  overflow 
attachment  of  the  gage  and  carefully  melted.  Observations  of 
precipitation  should  be  made  daily.  The  gages  are  preferably 
exposed  in  an  open  space  and  at  a  distance  from  trees,  buildings, 
or  high  fences.  "Low  bushes  and  fences,  or  walls  that  break  the 


PLANS  AND  RECORDS.  225 

force  of  the  wind,  are,  however,  beneficial,  if  at  a  distance  not  less 
than  the  height  of  the  object."  The  top  of  the  gage  is  placed  level 
and  about  three  feet  above  the  ground. 

The  elevation  of  the  water-surface  of  ponds,  lakes,  or  storage 
reservoirs  should  be  observed  periodically,  and  the  increase  or 
decrease  in  the  amount  of  water  in  storage  computed  from  the 
results  of  these  observations  and  the  data  regarding  the  extent 
of  water-surface  at  different  elevations.  Tables  or  diagrams  that 
indicate  the  volume  of  storage  corresponding  to  stated  elevations 
of  the  water-surface  are  useful  in  this  connection. 

The  draft  from  the  catchment  area  is  ascertained  from  pump- 
ing or  meter  records,  or  observations  of  the  flow  of  water  over 
weirs.  The  first-mentioned  records  are  likely  to  be  seriously  in 
error,  unless  the  slip  of  the  pumps  be  known  and  provided  for  in 
the  computations  of  pumpage. 

The  ordinary  type  of  water-meter  is  not,  as  a  rule,  used  for  the 
measurement  of  the  total  volume  of  water  supplied  to  a  city  or 
town;  the  Venturi  meter,  an  instrument  devised  by  Clemens 
Herschel,  C.E.,  being  used  for  this  purpose.  The  Venturi  meter 
consists  of  a  contracted  tube  composed  of  two  truncated  cones 
and  a  throat-piece  which  connects  the  smaller  ends  of  the  former. 
This  tube  is  placed  in  the  pipe-line.  When  water  is  flowing  through 
the  tube,  the  velocity  of  flow  is  greater  at  the  throat  than  at  the 
up-stream  end  of  the  tube,  and  the  pressure  at  this  point  is  less 
than  that  at  the  latter;  the  difference  in  pressure  being  dependent 
upon  the  quantity  of  water  flowing.  The  loss  of  head  due  to  the 
contraction  of  area  of  the  pipe  is,  under  ordinary  circumstances, 
insignificant.  The  up-stream  end  and  the  throat  of  the  meter- 
tube  are  connected  by  pipes  with  a  recording-apparatus,  which 
mechanically  integrates  the  varying  relations  of  velocity  and 
pressure  within  the  tube,  and  indicates  on  a  dial  the  amount  of 
water  which  has  passed  through  the  meter.  By  the  addition 
to  the  register  of  a  chart-recorder  the  rate  of  flow  at  intervals 
throughout  the  day  is  recorded  upon  a  strip  of  paper.  The  com- 
mon sizes  of  meter  are  from  six  to  sixty-inch,  and  the  meters  are 
designed  to  measure  flows  when  the  maximum  rate  does  not 
exceed  about  ten  times  the  minimum  rate  of  flow  through  the 
supply-main  in  which  the  meter  is  placed.  The  results  obtained 


226 


MAINTENANCE  AND  OPERATION. 


by  Venturi  meters  operating  under  suitable  conditions  are  accurate 
within  about  two  or  three  per  cent.  Forty-nine  Venturi  meters 
were  used  in  investigations  made  by  the  Metropolitan  Water  and 
Sewerage  Board  in  1903;  the  arrangement  of  the  meter  and  regis- 
tering-apparatus as  generally  used  being  shown  in  Fig.  43. 


Water-tight  Steel  Chamber  containing  I 
Meter  Register  placed  under  sidewalk  I 


Venturi  Meter  Tube 


A.  Chart-box  and  Chart 

B.  Weight  for  operating  register  mechanism. 

C.  Cylinder  containing  float  and  integrating  mechanism. 


Scale  of  Feet 


FIG.  43.— Venturi  Meter  and  Register  Chamber.    (Jour.  N.  E.  Water-works  Assoc'n, 

Vol.  XVIII,  p.  113.) 

The  flow  of  water  over  weirs  or  dams  is  computed  from  obser- 
vations made  of  the  height  of  water  above  the  crest  of  the  weir 
or  dam,  by  the  aid  of  formulas  adapted  for  use  with  the  condi- 
tions which  obtain  in  a  given  instance. 

The  yield  of  or  run-off  from  a  catchment  area  is  dependent 
upon  the  precipitation  upon  the  area,  and  the  evaporation  from 
the  land  and  water  surfaces.  The  amount  of  water  available 
from  the  area  is  determined  from  the  computations  of  yield  or 


PLANS  AND  RECORDS. 


227 


run-off;  these  computations  being  based  upon  the  observations  of 
the  quantity  of  water  in  storage,  the  draft,  and  the  waste  over 
dams  or  waste-weirs.  This  amount  varies  from  year  to  year,  and 
since  the  capacity  of  the  source  is  dependent  upon  the  minimum 
yield  and  the  opportunities  for  storage,  records  extending  over 
a  period  of  years  and  embracing  varied  conditions  are  of  great 
value  when  observations  are  accurately  made  and  the  data  care- 
fully compiled. 

The  average  results  obtained  from  observations  made  on  some 
existing  works  are  of  interest  in  this  connection  and  are  given  in 
the  following  table. 

AVERAGE  YIELD  OF  CATCHMENT  AREAS. 


Stream. 

Period  covered 
by  observations. 

Catchment  area. 
Square  miles. 

Average 
Rainfall. 
Inches. 

Average 
run  -off. 
Inches. 

Sudbtiry 

l87<?—  IOO4 

7C.2 

46  .  22 

22     717 

Wachusett 

1807—1004 

I  IQ.O 

CQ.  O7 

26     7  J.2 

Croton                .  .  . 

1868-1899 

338.8 

JW.   V/ 

48  .  07 

22     O3 

Perkiomen         .    . 

i883—  IQOC 

I  52  .  O 

47  .6"? 

2  3    O4 

Neshaminy      .  .    . 

1883—  IQOC 

I^O  .3 

47.82 

22    85 

Tohickon        .. 

1883—  IQOC 

IO2  .  2 

48  .  QI 

27    47 

The  extent  of  water-surface  on  a  catchment  area  affects  the 
total  evaporation  from  that  area  since  the  evaporation  from 
a  water-surface  exceeds  that  from  one  composed  entirely  of  land. 
In  order  that  the  yield  of  a  catchment  area  may  be  computed 
on  a  net  land  basis,  the  loss  from  the  water-surface  must  be  known 
or  estimated.  Such  computations  are  of  value  in  the  consideration 
of  problems  of  additional  supply,  when  the  proposed  sources  are 
in  close  proximity  to  sources  of  which  the  yield  is  known,  or  in 
the  consideration  of  the  effect  upon  the  yield  of  a  source  due  to 
the  construction  of  additional  impounding  reservoirs. 

Measurements  of  the  evaporation  from  a  water-surface  are 
made  with  a  floating  tub  or  tank  of  wood,  protected  in  such  man- 
ner that  water  may  not  be  introduced  into  it  from  the  pond  or 
reservoir  by  the  action  of  wind  or  waves.  Results  obtained  on 
the  Boston  Water-works  by  Desmond  Fitzgerald,  C.E.,  from  1875 
to  1890  indicated  that  the  average  evaporation  from  a  water- 
surface  in  that  vicinity  was  about  39.2  inches.* 

*  Trans.  Am.  Soc.  C.  E.  "Rainfall,  Flow  of  Streams,  and  Storage," 
Vol.  XXVII;  "Evaporation,"  Vol.  XV. 


228  MAINTENANCE  AND  OPERATION. 

This  was  distributed  throughout  the  year  as  follows: 

Month.                                                           Evaporation  in  Inches. 
January o .  96 

February i  .05 

March 1 . 70 

April , 2 . 97 

May 4.46 

June 5.54 

July 5-98 

August 5 .50 

September 4.12 

October 3.16 

November 2.25 

December 1.51 

Total 39 . 20 

The  average  results  obtained  at  the  Mount  Hope  reservoir  of  the 
Rochester  Water-works  since  the  beginning  of  experiments  in 
1891  are  as  follows:  * 

Month.  Evaporation  in  Inches. 

1896-1904  January 0.66 

1896-1904  February 0.84 

1896-1904  March i  .48 

1894-1904  April 2 . 71 

1892-1904  May 4. 03 

1892-1904  June. 4.80 

1891-1904  July 5.33 

1891-1904  August 4. 92 

1891-1904  September 4.01 

1891-1904  October 2.88 

1895-1904  November 1.52 

1895-1904  December i .  17 

Total 34.35 

The  records  of  consumption  are  based  upon  the  records  of 
draft  previously  mentioned,  with  corrections  applied  to  com- 
pensate for  the  gain  or  loss  in  the  quantity  of  water  contained 

*  Annual  Reports,  Rochester,  N.  Y.,  1904. 


PL/IKS  /tND  RECORDS. 


229 


in  distribution-reservoirs  or  stand-pipes.  Data  with  regard  to 
the  average,  minimum,  and  maximum  quantities  of  water  con- 
sumed daily,  weekly,  or  monthly  are  kept  by  a  number  of  water- 
works departments.  The  maximum  hourly  rates  of  consumption 
from  a  system  are  of  value  in  the  consideration  of  problems  of 
fire-protection. 

Several  recording  devices  are  in  use  for  the  determination  of  the 
various  elements  entering  into  computations  of  yield,  draft,  or 
consumption.  Continuous  records  of  the  height  of  water  on 
dams  or  weirs,  or  in  ponds,  reservoirs,  or  stand-pipes  may  be 


FlG.  44. — No.  2  Winslow  Electrical  Indicating  and  Recording  Apparatus. 

obtained  by  the  use  of  apparatus  consisting  of  floats,  indicating 
devices,  and  rolls  carrying  record-sheets  which  are  moved  by 
clockwork.  The  apparatus  illustrated  is  used  for  indicating  and 
recording  changes  in  water-level  which  take  place  at  a  point  distant 
from  that  at  which  the  recording  instrument  is  placed. 

When  reservoirs  or  stand-pipes  are  filled  by  pumps,  a  device 
indicating  the  height  of  water  in  the  reservoir  or  stand-pipe  is 
usually  placed  at  the  pumping-station.  An  alarm-bell  is  often 
provided  in  connection  with  these  devices  which  gives  warning 
when  the  water-level  approaches  high-water  mark.  In  cold  cli- 
mates the  formation  of  ice  on  the  reservoir  or  in  the  stand-pipe 
often  limits  the  use  of  appliances  depending  upon  a  float  for  their 
operation,  and  pressure-gages  are  used  for  a  like  purpose,  although 
the  results  obtained  with  these  instruments  are  not  as  accurate. 

Pressure-recording  gages  are  placed  in  offices,  pumping-sta- 


230  MAINTENANCE  AND  OPERATION. 

tions,  or  workshops,  and  these  instruments  are  often  of  value 
for  indicating  reductions  in  pressure  due  to  large  leaks  or  other 
causes,  and  as  a  check  upon  the  operation  of  the  pumps.  Such 
gages  should  be  attached  to  an  independent  supply-pipe  leading 
from  a  large  street-main,  and  the  connection  should  not  be  made 
near  branch-lines  serving  street-sprinkler  stand-pipes  or  large 
consumers. 

The  engineer  in  charge  of  the  pumping-station  should  be  pro- 
vided with  blank  forms  upon  which  details  with  regard  to  the 


FIG.  45. — Combined  Pressure  and  Recording  Gage. 

operation  of  the  station  should  be  noted  daily.  The  pumping 
records  should  be  kept  in  book  form  at  the  water-works  office  and 
the  daily  observations,  with  the  computations  based  thereon, 
entered  each  month.  The  data  may  be  recorded  somewhat  as 
follows:  Date;  time  of  starting  pumps;  time  of  stopping  pumps; 
duration  of  pumping;  reading  of  counter;  number  of  strokes  or 
revolutions;  gallons  pumped  (with  or  without  allowance  for  slip); 
reading  of  suction-gage;  reading  of  pressure-gage;  total  lift 
(static  and  dynamic);  reading  of  steam-gage;  amount  of  coal 


PLANS  AND  RECORDS.  23* 

consumed;  amount  of  ashes  and  clinkers;  per  cent  of  ashes  and 
clinkers;  quantity  of  feed-water;  temperature  of  feed- water;  duty. 
Care  should  be  taken  that  the  indications  of  the  gages,  scales, 
and  water-meters  are  substantially  correct. 

When  water  is  furnished  at  schedule  or  fixed  rates,  all  premises 
and  buildings  supplied  from  the  works  should  be  systematically 
inspected  at  intervals  and  the  results  of  the  inspections  entered  in 
an  inspection  record.  Dependence  should  not  be  placed  entirely 
upon  returns  made  by  consumers  or  plumbers  employed  by  them, 
as  almost  invariably  fixtures  are  placed  and,  through  the  careless- 
ness or  negligence  of  the  parties  responsible  for  the  work,  no 
returns  made  to  the  water-works  office.  The  item 3  may  be 
entered  in  the  inspection  record  under  the  following  headings: 
Service  number;  Street  and  number;  Owner  and  occupant  of 
premises;  Number  and  kind  of  fixtures  (separate  columns  are 
allowed  for  each  class  of  fixtures  ordinarily  supplied  and  for 
which  a  charge  is  made);  Use  to  which  water  is  applied;  Person 
to  whom  bill  is  made;  Amount  of  bill;  Remarks. 

The  water-bills  are  made  from  the  data  contained  in  this  record. 

Data  with  regard  to  meters  purchased  and  placed  by  the 
water  department  should  be  preserved  upon  forms  prepared  for 
that  purpose.  A  page  in  a  meter-record  book  or  a  card,  if  the 
card  system  is  in  use,  should  be  allowed  for  each  meter  and  the 
following  items  entered  thereon.  Meter  record:  Size;  Type; 
Make;  Manufacturer's  number;  Date  purchased;  Cost;  Date 
tested;  Result  of  test;  Date  re-tested;  Result  of  test;  Quantity 
registered  since  previous  test;  Date  set;  Location;  Date  removed; 
Date  reset;  Location;  Date  repaired;  Repairs  necessary;  Cost  of 
repairs. 

Records  of  the  amount  of  water  registered  by  service-meters 
should  be  kept  in  convenient  form  and  the  meter-bills  made 
therefrom.  The  entries  may  be  made  in  form  somewhat  similar 
to  the  inspection-record  form  previously  mentioned  except  that 
in  place  of  the  items  under  the  heading  "Fixtures  supplied"  the 
number,  size,  and  make  of  meter,  the  meter  readings,  and  the 
quantities  of  water  consumed  are  entered. 


CHAPTER   II. 

EXTENSIONS. 

EXTENSIONS  of  existing  works  are  called  for  from  time  to  time 
to  provide  for  the  constantly  increasing  demands  of  a  community, 
and  these  additions  to  a  system  often  require  careful  study.  In 
some  instances  the  extensions  are  made  in  accordance  with  a  pre- 
arranged scheme  evolved  by  the  engineer  responsible  for  the 
original  design;  in  others  the  matter  is  left  to  the  discretion  of  the 
board  or  commission  in  charge  of  the  works.  In  the  latter  case 
it  not  infrequently  happens  that  little  or  no  regard  is  given  to 
the  possible  future  demands  nor  to  the  requirements  for  fire 
protection,  with  the  result  that  many  distribution  mains  soon 
prove  inadequate,  particularly  for  the  latter  purpose.  It  may  be 
stated  that  as  a  general  rule  it  is  not  advisable  to  make  additions 
without  recourse  to  the  advice  of  a  competent  engineer. 

Usually  extensions  of  considerable  extent  may  be  made  more 
economically  through  the  medium  of  a  good  contractor,  but  small 
additions  may  be  made  by  day  labor.  Before  the  work  of  con- 
struction is  commenced,  the  location  of  the  pipe-line  should  be 
marked  on  the  ground  and  the  position  of  specials,  valves,  and 
hydrants  indicated  by  suitably  marked  stakes  or  by  other  means. 
A  detailed  plan  or  sketch  of  the  proposed  work  should  be  placed 
in  the  hands  of  the  foreman  in  charge,  and  no  deviation  from 
this  plan  should  be  permitted  without  the  consent  of  the  super- 
vising engineer.  In  case  surveys  are  not  made  during  the  course 
of  construction,  measurements  should  be  taken  to  all  points 
controlling  the  alignment,  in  order  that  such  points  may  be  accu- 
rately located  on  the  surface  when  the  surveys  are  carried  out. 

The  main  pipe-line  should  be  laid  at  a  uniform  distance  from 
the  street-line,  a  distance  approximately  equal  to  one-third  the 

232 


EXTENSIONS  233 

street  width  serving  as  a  guide  except  at  sharp  curves,  where, 
owing  to  the  decreased  friction  losses,  it  is  often  advisable  to  use 
special  fittings  instead  of  making  long  bends  in  the  alignment. 
The  depth  at  which  the  main  should  be  laid  is  dependent  upon 
the  locality  and  in  cities,  upon  existing  underground  structures. 
The  usual  practice  in  New  England  is  to  excavate  ordinary  trenches 
from  four  and  one-half  to  six  feet  in  depth.  However,  since  the 
fractional  losses  are  increased  by  abrupt  changes  in  the  alignment 
in  the  vertical  plane  as  well  as  in  the  horizontal,  due  regard  should 
be  given  to  the  grade  of  the  pipe-line. 

Valves  should  be  placed  to  control  districts  and  streets  in 
order  that  the  water  may  be  shut  off  for  repairs.  Valves  located 
on  branch  lines  should  be  set  exactly  on  the  line  of  the  street  in 
which  the  principal  main  is  laid,  even  if  such  location  necessitates 
the  cutting  of  a  pipe  to  accomplish  this  end.  Hydrant  connec- 
tions from  supply  or  other  important  mains  should  be  provided 
with  valves  for  use  in  making  repairs  to  the  hydrants. 

In  thickly  settled  communities  hydrants  should  not  be  placed 
more  than  500  feet  apart,  and  in  sparsely  settled  districts 
these  should  be  located  with  a  view  to  the  ultimate  location  of 
hydrants  at  intermediate  points.  Plugged  branches  may  be  left 
at  such  points  for  future  use.  Since  good  drainage  is  essential  to 
the  proper  operation  of  a  fire-hydrant,  care  should  be  taken  in 
their  setting.  In  fine,  compact,  or  clayey  material  the  hydrant 
should  be  underlaid  and  the  base  surrounded  with  coarse  grave^ 
bricks,  or  small  field  stones.  The  hydrants  should  also  be  backed 
with  heavy  stones,  brickwork,  or  concrete,  as  instances  are  on 
record  where  a  hydrant  has  been  forced  from  the  branch,  with 
consequent  damage  to  the  street  and  adjacent  property.  Inas- 
much as  there  is  little  or  no  circulation  in  the  connections,  care 
should  be  taken  to  set  the  inlet-valve  and  base  of  a  hydrant 
below  the  depth  ordinarily  reached  by  frost.  In  order  that  the 
projecting  nozzles  may  not  be  struck  and  broken  by  teams, 
hydrants  should  be  set  a  short  distance  inside  the  curb-line. 

Care  should  be  taken  in  the  work  of  construction  to  reduce  the 
obstruction  to  traffic  to  a  minimum,  and  all  trenches,  tool-boxes, 
etc.,  should  be  well  lighted  at  night.  For  economy  in  operation  the 
construction  force  should  be  divided  into  gangs,  each  performing 


234  MAINTENANCE  AND  OPERATION. 

a  special  duty;  for  instance,  one  party  may  excavate  the  trench 
in  advance,  another  attend  to  the  digging  of  bell-holes  and  the 
laying  of  the  pipe,  and  another  the  back-filling.  Whenever  pos- 
sible, however,  the  pipe-line  should  not  be  covered  until  the  water 
is  turned  on  or  the  joints  tested  under  pressure,  although  in  order 
to  prevent  the  caving  of  the  banks  the  trench  may  be  partially 
refilled  between  joints. 

Long  lines  of  pipe  should  not  be  left  entirely  exposed  to  the 
rays  of  the  sun  after  the  joints  have  been  calked,  as  the  expansion 


FlG.  46.— Pipe-derrick. 

and  contraction  of  the  line  resulting  from  the  heating  and  sub- 
sequent cooling  tends  to  start  the  joints. 

Stones,  sticks,  or  other  material  should  be  removed  from  the 
pipes  before  they  are  lowered  into  the  trench,  a  brush  attached 
to  a  long  pole  being  of  service  for  cleaning  the  smaller  sizes,  and 
the  end  of  the  pipe-line  should  be  protected  at  night  or  at  cessation 
of  work  by  a  cover  or  plug  of  wood. 

The  smaller  sizes  of  pipe  can  be  lowered  into  the  trench  by 
means  of  sling-ropes  handled  by  men  on  the  banks,  but  the  heavier 


EXTENSIONS.  235 

pipes  require  the  use  of  a  derrick  and  skids.  The  pipe  to  be 
lowered  is  placed  on  skids  over  the  trench  and  then  handled  by 
blocks  and  falls  attached  to  a  derrick.  The  derrick  may  be  a 
special  pipe-derrick  (Fig.  46)  or  one  of  the  tripod  type.  The 
latter,  when  the  upper  block  is  provided  with  a  catch  by  means  of 
which  the  weight  can  be  held  in  any  position,  will  also  be  found 
very  useful  in  setting  hydrants,  large  valves,  and  raising  large 
stones  from  the  trench. 

Small  pipes  should  never  be  permitted  to  rest  upon  the  bell 
alone;  the  bottom  of  the  trench  being  carefully  excavated  in  order 
that  the  pipe-barrel  may  have  a  continuous  bearing.  Mains  of  two 
feet  and  more  in  diameter  are  usually  supported  upon  blocks  and 
wedges,  in  which  case  the  back-filling  should  be  well  compacted 
under  and  about  the  pipe.  The  blocks  and  wedges  should  be  of 
sound  wood,  the  blocks  being  from  two  to  four  feet  long,  eight  to 


FIG.  47. — Go  wing  Pipe- jointer. 

twelve  inches  wide,  and  three  to  six  inches  thick;  the  wedges,  twelve 
to  eighteen  inches  long,  four  to  six  inches  wide,  and  three  to  four 
inches  thick  at  one  end,  tapering  to  a  thickness  of  one-half  inch 
at  the  other,  depending  upon  the  size  of  the  pipe  and  the  nature 
of  the  foundation  soil.  Two  sets,  i.e.  two  blocks  and  four  wedges, 
are  placed  under  each  pipe. 

The  pipe-joints  should  be  carefully  filled  to  the  proper  depth 
with  yarn  of  good  quality,  care  being  taken  to  preserve  the  bore  of 
the  line  continuous.  The  lead  should  be  soft  and  of  good  quality 
and  the  joint  completely  filled  at  one  pouring,  the  lead  extending 
to  the  back  of  the  groove  cast  on  the  interior  of  the  bell.  The 
old-time  clay  roll  used  in  leading  the  joints  has  been  superseded 
by  the  many  patent  pipe-jointers  made  of  asbestos  or  rubber  now  on 


236 


MAINTENANCE  AND  OPERATION. 


the  market,  the  use  of  which  effects  a  saving  in  time  and  material. 
The  yarning  and  calking  should  be  accomplished  by  experienced 
men  furnished  with  suitable  tools  for  the  purpose.  The  lead 
is  usually  melted  in  a  furnace  similar  to  the  one  shown  in  the 
accompanying  illustration.  The  yarn,  which  should  be  free  from 
tar,  is  driven  tightly  into  the  bell  with  a  yarning-iron,  and  after 
the  joint  is  poured  the  lead  is  compacted  by  a  calking-iron. 
These  irons  are  of  the  form  shown  by  the  illustrations,  a  set  of 
tools  consisting  of  a  hammer,  a  cold-chisel,  a  yarning-iron,  and 


FIG.  48. — Lead  Kettle  and  Furnace. 

six  calking-irons  having  calking  edges  varying  in  thickness  from 
one-eighth  to  three-quarters  of  an  inch.  Superfluous  lead  is  cut 
away  with  a  cold-chisel. 

Pipe  may  be  cut  when  necessary  by  the  use  of  a  pipe-cutting 
chisel  (see  Fig.  49).  The  pipe  to  be  cut  should  be  supported 
by  planks  or  joists  and  should  be  slowly  rolled  along  the  supports 
while  the  chisel  is  struck  with  a  heavy  sledge-hammer.  A  light 
cut  should  be  first  made  entirely  around  the  pipe.  This  cut  is 
made  deeper  by  successive  operations,  during  whch  the  force  of  the 
blow  upon  the  chisel  is  increased,  until  the  pipe  parts. 

The  manner  in  which  the  refilling  of  the  trench  is  accomplished 
is  dependent  upon  local  conditions  and  the  character  of  the  material. 
When  after-settlement  is  not  desirable,  resort  must  be  made  to 


EXTENSIONS.  237 

thorough  ramming  with  suitable  tampers,  the  earth  being  deposited 
in  four-  to  six-inch  layers,  wet  thoroughly,  covered  with  a  few  inches 
of  dry  material  and  then  well  tamped.  Care  should  be  taken  to 
consolidate  the  material  at  the  edges  of  the  trench,  and  the  finished 
surface  should  be  left  slightly  crowned  at  the  center.  Valve-boxes 
should  be  set  with  the  covers  at  the  original  grade  of  the  street- 
surface.  Trenches  in  suburban  streets  or  roads  may  be  refilled 
more  economically  by  depositing  the  material  in  water  or  by 
flooding  the  trench  after  the  earth  has  been  back-filled  loosely  in 
layers,  but  puddling  or  flooding  should  not  be  carried  out  with  clay 
or  earth  containing  a  large  proportion  of  that  material.  Previous 


Cutting  Chisel.  Calking  Hammer. 


Yarning  Iron,  Calkin8  Iron' 

FlG.  49. — Pipe-laying  Tools. 

to  the  rilling  of  a  trench  with  water,  sufficient  earth  should  be 
placed  about  the  pipe  to  prevent  its  displacement. 

All  materials  should  be  inspected  before  acceptance  on  the 
work,  and  the  spigot  ends  of  cast-iron  water-pipes  should  be  re- 
examined  before  the  pipes  are  lowered  into  the  trench.  Material 
rejected  for  any  cause  should  not  be  allowed  to  remain  upon  the 
work,  but  should  be  removed  immediately. 

Materials. 

The  weight  of  cast-iron  pipe  to  be  used  and  the  selection  of 
valves  and  hydrants  is  governed  more  or  less  by  the  standards  in 
use  on  the  works,  and  a  change  in  the  type  or  make  of  valves  or 
hydrants  is  not  desirable  unless  experience  has  demonstrated  that 
a  departure  from  existing  custom  is  advisable. 


238  MAINTENANCE  AND   OPERATION. 

The  use  of  cast  iron  for  the  mains  of  a  distribution  system  is  now 
the  general  practice,  and  the  New  England  Water-works  Associa- 
tion has  developed  a  set  of  standard  specifications  for  pipe  and 
special  castings  of  that  material  which  serves  as  an  admirable  guide 
in  the  purchase  of  these  supplies.  With  regard  to  the  thickness  of 
pipe  for  water-mains  the  committee  of  the  above  association  re- 
ported: "  The  thicknesses  given  in  Table  No.  2  were  computed  by 
the  following  formula,  which  is  one  used  in  determining  the  thick- 
ness of  pipe  used  on  the  Metropolitan  Water-works,  which  supply 
water  to  Boston  and  other  cities  and  towns  within  a  radius  of  ten 
miles;  Class  A  being  for  a  static  head  of  fifty  feet,  Class  B  for  one 
hundred  feet,  etc.,  each  class  advancing  by  fifty  feet.  This  formula 
provides  factors  for  the  deterioration  of  the  pipe  by  time  and 
other  conditions,  for  the  internal  strain  due  to  the  static  head 
and  to  water-hammer,  but,  as  has  been  previously  stated,  other 
conditions  must  also  be  considered. 


3300 

in  which  t  =  thickness  in  inches; 

p  =  static  pressure  in  pounds  per  square  inch; 
P'  —  pressure  in  pounds  allowed  for  water-hammer; 
r  =  internal  radius  of  pipe  in  inches; 
3300  =  5  tensile  strength  of  cast  iron,  taken  to  be   16,500 

pounds  per  square  inch; 

0.25  =  allowance  for  deterioration  by  corrosion   and  other 
causes. 

Values  given  to  P'  as  follows: 

Diameter  of  Pipe.  P'  in  Pounds. 

4-,  6-,  8-,  and  lo-inch  ...................  120 

12-  and  14-inch  ........................  no 

16-  and  i8-inch  ........................  100 

20-inch  ................................  90 

24-inch  ................................  85 

3O-inch  ................................  80 

36-inch  ................................  75 

42-  to  6o-inch  ..........................  70 


EXTENSIONS.  239 

"  The  committee  does  not  recommend  the  classification  of  the 
weights  upon  the  basis  of  static  head,  believing  that  to  the  engineer 
or  superintendent  should  be  left  the  final  decision  as  to  the  thickness 
or  weight  of  pipe  suitable  for  the  particular  place  in  which  it  is 
to  be  used."  * 

The  following  tables  show  the  "General  Dimensions  of  Pipes  and 
Special  Castings"  and  the  "Standard  Thicknesses  and  Weights 
of  Cast-iron  Pipes"  adopted  by  the  New  England  Water-works 
Association. 

The  hydrants  in  general  use  in  small  cities  and  towns  are  of 
the  type  known  as  "post"  hydrants;  the  "flush"  hydrant  being 
rarely  seen  outside  the  large  cities.  Hydrants  of  the  first  class 
project  above  the  surface,  and  the  nozzles  and  upper  portion  of  the 
valve-rod  are  above  the  level  of  the  sidewalk;  those  of  the  second 
are  entirely  enclosed  in  masonry  chambers  built  below  the  surface 
of  the  street.  The  details  of  the  valve  controlling  the  supply  of 
water,  its  position  when  the  hydrant  is  in  use,  and  the  operating 
mechanism  vary  widely  in  the  several  designs  of  post  hydrants 
manufactured.  The  main  valve  consists  of  a  number  of  leather 
disks  held  in  place  on  the  valve-rod  by  nuts  and  metal  washers, 
or  is  made  of  metal,  which  in  some  designs  is  faced  with  leather  or 
rubber.  Hydrants  supplied  with  water  by  a  valve  of  the  first  type 
are  usually  termed  "  plug"  or  "compression"  hydrants;  those 
with  metal  or  faced  metal  valves  which  move  in  a  vertical  plane, 
"gate"  hydrants.  The  distinctive  features  of  the  two  types  are 
shown  by  the  illustrations.  A  waste  or  drip  is  usually  provided  for 
the  purpose  of  draining  the  water  from  the  hydrant  after  use. 
The  following  details  should  be  given  consideration  in  the  selection 
of  the  make  of  hydrant  to  be  used: 

Simplicity  of  operation; 

Accessibility  of  valve  and  operating  mechanism; 

Durability; 

Ease  and  cost  of  making  repairs; 

Drainage; 

Area  of  water-way  and  loss  of  pressure  due  to  friction; 

Liability  of  water-hammer; 

Liability  of  leakage  when  used  frequently. 

*  Jour.  N.  E.  Water-works  Assoc'n,  Vol.  XVI,  pp.  89-90. 


240 


MAINTENANCE  AND  OPERATION. 
GENERAL  DIMENSIONS  OF  PIPES  AND  SPECIAL  CASTINGS. 


Nominal 

Actual 

Diameter  of 
sockets. 

Depth  of  sockets. 

diame- 
ter, 
inches. 

Classes. 

outside 
diameter, 
inches. 

.Pipe, 
inches. 

Special 
castings, 
inches. 

.Pipe, 

inches. 

Special 
castings, 
inches. 

a 

b 

4 

A,  C,E 

4.80 

5  -60 

5-70 

3  .  oo 

4.00 

•5° 

I.30 

4 

G,  I,K 

5  -°o 

5.80 

5-70 

3  -0° 

4.00 

•5° 

1.30 

6 

A,  C,  E 

6.90 

7-77 

7.80 

3-oo 

4.00 

•5° 

1.40 

6 

G,  I 

7.10 

7.90 

7.80 

3-oo 

4.00 

•5° 

1.40 

8 

A,  C,  E 

9-°5 

9-85 

10.  OO 

3-5° 

4.00 

•5° 

1.50 

8 

G,I 

9-3° 

IO.  10 

IO  .  OO 

3-5° 

4.00 

•5° 

1.50 

IO 

A,  B,C,  D 

II  .  IO 

II  .90 

12.10 

3-5° 

4-5° 

•5° 

1.50 

IO 

E,  F,  G,  H 

ii  .40 

12.20 

12  .  10 

3-5° 

4-5° 

•50 

1.50 

12 

A,  B,  C,  D 

13.20 

14.00 

14.  20 

3-5o 

4-5° 

•So 

I.  60 

12 

E,  F,  G,  H 

I3-5° 

14.30 

14.  20 

3-5° 

4-5° 

I  .60 

14 

A,  B,  C,  D 

15-3° 

16.  10 

16.35 

4-5° 

•50 

1.70 

14 

E,  F,  G,  H 

16.45 

16.35 

3-50 

4-5° 

•5o 

1.70 

16 

A,  B,C,  D 

17.40 

18.40 

18.60 

4.00 

5  -0° 

•75 

I.  80 

16 

E,  F,  G,  H 

17.80 

18.80 

18.66 

4.00 

r  .  OO 

•75 

I.  80 

18 

A,  B 

i9-25 

20.  25 

20.40 

4.00 

S-oo 

•75 

I  .90 

18 

C,  D 

19.50 

20.50 

20  .  40 

4.00 

5  -o° 

•75 

1.90 

18 

E,  F 

19.70 

20.  70 

20.  70 

4.00 

5  -oo 

•75 

I  .90 

20 

A,  B 

21.30 

22.30 

22  .  50 

4.00 

5  •  oo 

•75 

2.00 

20 

C,  D 

2  I  .  60 

22  .  60 

22  .  50 

4.00 

5  -o° 

•75 

2.00 

20 

E,F 

21.90 

22  .90 

23.00 

4.00 

5  -oo 

•75 

2.00 

24 

A  B 

25.40 

26  .40 

26.60 

4.00 

5  -0° 

2  .OO 

2.10 

24     . 

C,  D 

25.80 

26.80 

26  .60 

4.00 

c  .  OO 

2  .OO 

2.10 

24 

E,  F 

26  .  10 

27  .  10 

27  .  10 

4.00 

5-oo 

2  .OO 

2.10 

3° 

A,  B 

31.60 

32.60 

32.60 

4-5o 

5-oo 

2  .OO 

2.30 

3° 

C,  D 

32.00 

33  •  oo 

33-0° 

4-50 

5.00 

2  .OO 

2.30 

3° 

E,  F 

32.40 

33-40 

33-40 

4-5° 

5-oo 

2.OO 

2.30 

36 

A,  B 

37.80 

38.80 

38.80 

4-5° 

5  •  oo 

2  .OO 

2.50 

36 

C,  D 

38.30 

39-30 

39-30 

4-5° 

5.00 

2  .OO 

2.50 

36 

E,F 

38.70 

39-7° 

39-7° 

4-5° 

5-oo 

2  .  OO 

2.50 

42 

A,  B 

44.00 

45-0° 

45-0° 

5  .00 

5  •  oo 

2  .00 

2.80 

42 

C,  D 

44.50 

45-5° 

45-5° 

5  -oo 

5  -oo 

2  .OO 

2.80 

42 

E,F 

45.10 

46.  10 

46  .  10 

5  -0° 

5  -0° 

2  .00 

2.80 

48 

A,  B 

5O.  2O 

51  .  20 

51  .  20 

5.00 

5  -0° 

2  .00 

3  .  oo 

48 

C,  D 

5O.  80 

51.80 

51.80 

5-oo 

5  -oo 

2  .00 

3.00 

48 

E,  F 

51  .40 

52.40 

52.40 

5-oo 

5.00 

2  .00 

54 

A,B 

56.40 

57-40 

57-40 

5-50 

5-50 

2.25 

3-2° 

54 

C,  D 

57-10 

58.10 

58.  10 

5-5° 

5-5o 

2.25 

3.20 

54 

E,F 

57.80 

58.80 

58.80 

5-50 

5-5o 

2.25 

3.80 

60 

A,  B 

62  .60 

63.60 

63  .  60 

5-5° 

5-5° 

2.25 

3-40 

60 

C,  D 

63.40 

64.40 

64  .  40 

5-5° 

5-5° 

2.25 

3-40 

60 

E,F 

64.  20 

65.20 

6  s  .  ?o 

5  .  <o 

5-5o 

2.25 

4  .  OO 

EXTENSIONS. 


241 


ONOX  4k  4k 
O  4*   00  M 

CA»  C*»    K>    10 

Ov  0  4k   O 

M     M     IH     M 
00  ON4k     K> 

O   OOON4* 

Nominal  diameter 
of  pipe. 

M      M     O      O 

0    0    0    O 

O    0    O    O 

0000 

tj*    Thickness 
w         of  shell. 

> 

M   O  O   00 

SL££L££L±2 

•^J  -0    O\  ON 
0    M  4-    0 

cyica  <J\  4k 

^J  C^l  CA>  O 

4k  4k  Oo  OJ 

~-I    K>     00  4^ 

OO-vJ   ON4k 
vO  Oi    M  vo 
O   MO*   U 
0000 

Os>     IO    (0    M 

00  00  O    ON 
O    C\C/l    w 
0000 

4k    w   O   00 

O      M      M      M 

O  en    O    O 

ON4k  Oo    K) 
01  ^J  GJ   O 
O  01    O    O 

g    Weight  per 
$        length. 

M      M     W      11 

0    0    O    0 

O    0    0    0 

0 
Ol 

o 

fc1    Thickness 
3         of  shell. 

to 

C*»  M  M  O 

0000 

O    00-vj    ON 
0    -i    10    ON 

ON  ONC/T  C/l 
Cs>     O   ^J  OJ 

HI 

O    CO  ONOi 
Oo    ONvO  Oi 
O   0  ^r  0\ 
O   O   O  O 

4k  Oo    K)    M 
13    M    K>  ^J 
^J  C*>  \O    ON 

o  o  o  o 

ca  OJ    O    00 
K>    O    CCOt 

O   O   O  en 

ON 

00 

O 

C    Weight  per 
w         length. 

M      W     M      M 

M    0    O    O 

O   O    O   0 

o  o  o  o 

V    Thickness 
3         of  shell. 

Q 

P 
I 
0 

(/!<*»  k»  IH 

O  ^J  Oi  O-> 

O  O    00-vi 

K>     «     0     M 

ON  ON  ONCa 
O  Cn    I-"  *si 

01  4k  4k  Co 

Oo    00  W    CN 

M  vo  ^-T   ON 

VO     OO\O     K> 
O    O    M  *N» 

o  o  o  o 

«<JOl  Oo    K> 

K)  Go  Ol    M 

O    O   O  ox 

£    Weight  per 
y          length. 

00  ONC^I  vO 
-t-    O  <-n    w 
O   O   O   O 

ONU>     M  VQ 

ONVO  01   M 
O    O   O   O 

O 

Ol 

ON 

ET    Thickness 
p         of  shell. 

Q 

P 
K 
O 

«*O«4k  M 

O  4k    O  ^J 

w    O    OO^J 
OJ     M     OOVO 

^j  ^i  ON  ON 
On    O    ^  M 

Oo    O    00  ON 
Oo  \O  ^J  vo 
8O  Oo-<r 
000 

tfl  CM    «0    (0 

OJ  vo  *a   O 
w  ca   OOO 
O   O   O    0 

M     M     M 
^1   4k     K)  O 

OOO    K»  *<r 
O    O   O   O 

-<r 

ON 

O 

£    Weight  per 
$         length. 

o  o  o  o 

o  o  o  o 

t?    Thickness 
*         of  shell. 

Class  E. 

\O  -a  Oi  4k 

O     N>  Ol    O 

K)    M  vo    00 
Cn    O  c^i  c_n 

Oo^r  ^i   ON 

O  Ol    O  Ol 

ONOi  4k  Oo 

O  Oo    CNO 

M      M 

Oi   K>  vo  ^J 
IH  4k  -^j  ^» 
8O  4k  K> 
O    O    O 

trt  4k  CA*    » 

\O  OJ    O    K> 
O  4^    0    ON 
0000 

\O    ONOo    O 

M      M      M    4k 

0000 

OCOl  OO    K> 

M  ^1     OOOO 

O  Oi    O    O 

5    Weight  per 
w          length. 

o  o  o  o 

O 

ON 
Oo 

a'    Thickness 
«         of  shell. 

Class  F. 

M  \O  ~-J  Ol 

O    O    O  Oo 

Cs>     K3     O    O 

«^I    O  Oo    M 

00  OO^J    ON 
ON  O  01  O 

CNOo    O    00 
Oi  Oi   CNOo 
O    0    0    ON 
0000 

ON4k  CA>    (0 

4k  ^i   M  4k 
0   0  4k    K> 
0000 

(0     M     M     M 

O   "^i  Os>      M 

4k    IH  vo    O 
O    O    O    O 

00 
Ol 

o 

£    Weight  per 
y         length. 

OOO 

OOOO 

Sr1    Thickness 
y         of  shell. 

Class  G. 

Oo^r  ^r 

Oi  O  OJ 

ONOl  Ol  4k 
•>-J    OO  O     K> 

004».  M 

M    ON  ON 
000 

Oo  r  —  K> 

vo  4k    M  Oi 
OOOO 

^    Weight  per 
w         length. 

OOO 
vo  oo-^r 

O  OJ  ^J 

o 

•>J 

o 

V    Thickness 
3         of  sheU. 

e 

B 

K 

VO  Oi    K) 

O  C*>    »0 
000 

vO 
Oo 

01 

C    Weight  per 
y         length. 

000 

ONOi  4k 
Oo  4k  Oi 

a"1    Thickness 
."         of  shell. 

Class  I. 

ON4k     M 
0  4^    Cx 
O  Ox  Oi 

C    Weight  per 
?          length. 

O 

4k 
00 

31    Thickness 
»          of  shell. 

o 

I 

w 

to 
00 
O 

£    Weight  per 
?          length. 

242 


MAINTENANCE  AND  OPERATION. 


FIG.  50. 
Section  of  Eddy  Hydrant. 


FIG.  51. 
Chapman  Hydrant. 


FIG.  52. 
Mathews  Hydrant. 


EXTENSIONS. 


243 


Post  hydrants  provided  with  two  2|-inch  hose  nozzles  and  one 
steamer  nozzle  will  usually  prove  satisfactory  for  general  use. 
Frost-cases  may  usually  be  dispensed  with,  but  are  occasion- 
ally needed  when  hydrants  are  set  in  clay  soils. 

The  valves  used  in  street-mains  are  usually  iron-body  valves 
with  bronze  mountings,  the  wedge  of  which  is  operated  by  an 
inside  screw.  Valves  made  entirely  of  iron  are  not  suitable  for 


FIG.  53. 
Ludlow  Hvdrant. 


FIG.  54. 
Corey  Hydrant. 


FIG.  55. 
Walker  Hydrant. 


water-works  use.  The  upper  end  of  the  screw  or  stem  is  capped 
with  a  square  iron  nut,  and  the  screw  is  turned  by  an  iron  or  steel 
rod  with  a  socket  on  the  lower  end  which  fits  over  the  nut,  the 
latter  being  made  accessible  by  the  use  of  a  cast-iron  valve-box. 
The  pattern  of  wedge  used  is  the  chief  feature  of  difference  in  the 
various  makes;  the  wedges  of  certain  valves  being  cast  as  a  single 
piece,  and  those  of  others  consisting  of  two  or  more  parts  which 
are  held  together  by  the  stem.  Valves  provided  with  a  divided 
wedge  are  termed  "adjustable-wedge"  valves. 


244 


MAINTENANCE  AND  OPERATION. 


The  smaller  valves  are  usually  placed  in  a  vertical,  and  those 
larger  than  eighteen  inches  in  size  in  a  horizontal,  position.  In 
the  latter  cases  gearing  is  required  for  the  operation  of  the  valve. 
The  largest  valves  are  provided  with  a  by-pass  by  which  the  pres;- 


FIG.  56. — Section  of  Chapman  Valve.  FIG.  57. — Coffin  Valve. 

sure  on  the  sides  of  the  wedge  is  equalized  when  the  valve   is 
opened,  and  are  enclosed  in  masonry  manholes. 

Sectional  extension  valve-boxes  are  placed  over  the  smaller 
valves.  Three  designs  of  boxes  are  shown.  Boxes  composed 
of  sections  which  have  no  mechanical  connection  are  preferable 
in  streets  where  the  traffic  is  heavy,  as  the  boxes  with  sections 
having  threaded  joints  are  more  easily  broken  by  road-rollers  and 
heavy  teams. 


EXTENSIONS. 


245 


Estimates  of  Cost. 

Estimates  of  the  cost  of  proposed  work  are  based  upon  the 
prevailing  prices  of  materials  and  the  wages  paid  in  the  locality 


A-Case 

B-  Cover  or  Bonnet 
C-Stem  or  Spindle 
D-Packing  Plate  or 

Stuffing  Box 
E-Stuffing  Box  Gland 

or  Follower 


M 


GG- Gates 
H- Gate  Rings 
I  -Case  Kings 
J— Top  Wedge 
K    Bottom  Wedge 
|_—  Throat  Flange 

Bolts 
M- Stuffing  Box  or 

Follower  Bolte 


FIG.  58.— Section  of  Ludlow  Valve. 

where  the  work  is  to  be  done.  The  preparation  of  estimates  of 
cost  is  facilitated  by  the  use  of  tables  or  diagrams.  The  cost  of 
cast-iron  water-pipe  is  the  principal  factor  in  computations  of  cost 
of  pipe-lines,  and  this  cost  is  usually  from  $25.00  to  $30.00  per  ton, 
but  often  the  quotations,  particularly  for  the  smaller  sizes,  exceed 
these  figures.  Fig.  61  shows  the  cost  per  foot  at  varying  prices 


246 


MAINTENANCE  AND  OPERATION 


per  ton  of  2000  Ibs.  of  the  several  sizes  of  cast-iron  water  pipe 
from  4  to  24  inches  in  diameter,  included  in  Classes  A,  C, 
and  E  of  the  New  England  Water- works  Association.  A  similar 
diagram  based  upon  the  actual  weights  of  pipe  in  use  in 


A-Stem  Nut 
B— Stem 
C— Follower 
D— Follower  Bolts 
E- Stuffing  Box 
F- Cover 


G-Body 

H  —Body  and  Cover 

Bolts 
I— Ball 
J  —  Gate 
K— Gate  Ring 
-  Case  Ring 


FIG.  59. — Section  of  Eddy  Valve. 

a  given  instance  can  be  readily  prepared  and  will  often  be  found 
convenient  in  estimating.  The  value  of  the  diagram  will  be 
increased  if  to  the  cost  of  the  pipe  per  foot  be  added  the  cost 
per  foot  of  pipe-laying,  etc.  The  latter  may  be  ascertained  from 
figures  obtained  from  actual  work  previously  performed,  and  three 
lines  may  be  drawn  upon  the  diagram  for  each  size  of  pipe:  one 


EXTENSIONS.  247 

representing  the  total  cost  per  foot  when  the  excavation  is  con- 
sidered easy,  one  when  this  is  difficult,  and  a  third  when  average 
conditions  are  encountered. 

The  cost  of  excavating,  back-filling,  and  pipe-laying  per  linear 
foot  of  trench  under  the  average  conditions  which  obtain  in  small 
cities  and  towns  in  New  England  is  about  as  follows: 

Size  of  pipe,  inches.  .  ..4       6       8       10      12      14     16      18     20     24        30 
Cost  per  foot,  cents.. ..    18     21     25     30     35     42     50     60     70     95     $1.30 


FIG.  60. — Valve-boxes. 

The  cost  of  rock  excavation  averages  from  83.00  to  $4.00  per 
cubic  yard. 

From  ij  to  ij  Ibs.  of  lead  are  required  for  each  inch  of  internal 
diameter  for  making  joints  in  cast-iron  pipe  lines;  i.e.,  the  lead 
required  for  a  6-inch  pipe- joint  varies  from  about  7^  to  loj  Ibs. 
The  pig  lead  used  for  joints  costs  from  4^  to  5  cents  per  pound. 
The  amount  of  yarn  required  for  joints  varies  from  0.05  to  o.i  Ib. 
per  inch  of  internal  diameter.  The  cost  of  yarn  or  jute  is  from  4 
to  4J  cents  per  pound. 

Valves  for  water-mains  cost  about  as  follows  when  purchased  in 
small  quantities: 

Size,  inches 46         8         10        12        14      16          18          20          24 

$6     $10     $14     $22      $28      $44     $60       $80      $100      $140 

Cost \    to       to       to       to       to       to       to        to         to         to 

$8     $13     $20     $28     $36     $54     $75     $100     $125     $180 


MAINTENANCE  AND  OPERATION. 


Valve-boxes  cost  from  $2.75  to  $4.00  each. 

Post  hydrants  with  6-inch  connections,  two  2  J-inch  hose  nozzles 
and  one  steamer  nozzle  cost  from  $25.00  to  $31.00  each.  Frost- 
cases  are  from  $2.00  to  $3.00  additional. 


8  S 

§L  §1  **>  s» 

qooj  *B(L  adi j  jo  ^s.oo 
FIG.  6 1. — Cost  of  Cast-iron  Pipe. 


Special  castings  are  either  sold  by  the  piece  at  varying  rates  of 
discount  from  established  lists  or  by  the  pound  at  the  market  price 
for  castings. 


CHAPTER  III. 

SERVICE  CONNECTIONS. 

THE  link  between  the  street-main  and  the  interior  piping  on  the 
premises  of  the  consumer  is  the  service  connection.  As  a  measure 
of  precaution  against  possible  leakage  due  to  poor  workmanship, 


FIG.  62. — Hall  Tapping-machine. 

imperfect  fittings,  or  the  use  of  pipe  of  inferior  grade,  and  un- 
authorized connections,  made  either  with  the  mains  or  under- 
ground service-pipes,  all  service-pipes  and  fittings  from  the  street- 
main  to  and  including  the  stop  and  waste  cock  on  the  applicant's 
premises  should  be  furnished,  laid,  and  maintained  by  the  water 
department.  A  proper  charge  may  be  made  the  consumer  for 
the  portion  ot  the  connection  which  is  outside  the  limits  of  the 
street  or  way,  and  an  additional  charge,  if  such  is  the  custom,  for 
the  tap  and  street  connection. 

249 


250  MAINTENANCE  AND  OPERATION. 

The  service  connection  consists  of  the  tap  or  corporation  cock 
in  the  main  pipe,  a  lead  gooseneck,  a  curb-cock  with  suitable 
box,  a  stop  and  waste  cock  on  the  consumer's  premises,  and  all 
intervening  piping. 

The  main  pipe  is  tapped  and  the  corporation  cock  screwed  in 
place  by  a  tapping-machine  designed  to  operate  with  the  main 
under  pressure.  There  are  several  good  machines  for  this  purpose 
on  the  market,  one  of  which  is  shown  in  Fig.  62. 


FIG.  63. — Service-clamp  (Mueller  Pattern). 

The  check  on  the  tap  and  drill  should  be  adjusted  to  allow  the 
corporation  cock  to  project  through  the  pipe  wall  about  one-half 
to  three-quarters  of  an  inch,  otherwise  the  tuberculation,  which 
takes  place  on  the  interior  of  the  main  more  rapidly  at  this  point 
as  a  result  of  the  injury  to  the  protective  coating,  will  slowly  but 
effectually  close  the  opening.  The  corporation  cock  is  usually 
of  the  same  diameter  as  the  service-pipe,  but  as  it  is  inadvisable  to 
make  large  taps  in  small  mains,  since  a  good  contact  between  the 
threads  on  the  cock  and  in  the  main  is  impossible  and  the  resulting 
joint  possesses  little  strength  or  rigidity,  it  is  occasionally  necessary 
to  make  several  taps  and  combine  the  goosenecks  when  large 
service  connections  are  laid.  The  use  of  several  taps  may  be  obvi- 


SERVICE  CONNECTIONS. 


251 


ated  by  the  use  of  a  tapping-band  or  service-clamp,  which  insures 
that  the  corporation  cock  will  be  held  firmly  in  place.  These  bands 
are  drilled  and  tapped  for  the  reception  of  the  corporation  cock, 
bolted  about  the  main  pipe,  and  the  connection  made  in  the  usual 


With  Straight  Coupling.  With  Bent  Coupling. 

FIG.  64. — Corporation  Cocks. 

manner.     Leakage  is  prevented  by  the  use  of  a  rubber  gasket,  and 
cement  or  lead  placed  in  a  groove  cast  in  the  band. 

As  a  general  rule  the  smaller  mains  are  tapped  on  top,  and  the 

Wiped  Joint 


Cup  Join* 


FIG.  65. — Gooseneck. 

larger  on  the  side.  In  the  first  instance  corporation  cocks  with 
bent  couplings  are  used,  and  in  the  second,  those  with  straight 
couplings. 


FIG.  66  —Corporation  Cock  with  Lead  Flange-coupling. 

Unless  lead  pipe  is  used  for  the  service,  a  lead  gooseneck 
about  two  feet  long  is  placed  between  the  corporation  cock  and 
the  service-pipe,  care  being  taken  that  the  upper  portion  of  the 


252 


MAINTENANCE  AND  OPERATION. 


bend  is  not  placed  too  high  in  localities  where  the  ground  freezes 
near  the  main  pipe.  The  gooseneck  is  provided  as  a  safeguard 
against  excessive  strain,  due  to  the  settlement  of  either  main-  or 
service-pipe  resulting  from  excavations  for  sewers  or  drains. 

The  joint  between  the  corporation  cock  and  the  gooseneck 
may  be  made  with  solder,  either  a  "wiped"  or  a  "cup"  joint  being 


Stop  and  Waste  Cocks  for  Iron  Pipe. 


Stop  and  Waste  Cocks  for  Lead  Pipe. 


Union-joint  Stop  and  Waste  Cocks  for  Lead  Pipe. 
FIG.  67.— Stop  and  Waste  Cocks. 

made,  or  the  solder  may  be  omitted  and  the  connection  made 
with  a  lead  flange-coupling.  The  "wiped  "  joint  presents  a  more 
workmanlike  appearance,  but  the  "cup"  joint  when  properly 
made  has  given  entire  satisfaction  and  requires  less  labor  and 
material.  The  lead  flange-coupling  consists  of  a  special  union 
in  which  the  end  of  the  lead  pipe  is  spread  and  flattened  with 


SERVICE  CONNECTIONS. 


253 


suitable  tools  to  form  a  gasket  for  the  joint.  The  material  costs 
about  the  same  as  that  for  the  "  wiped  "  joint,  but  the  joint  does 
not  require  the  skilled  labor  necessary  in  the  latter  instance. 

The  corporation  cocks  and  the  stop  and  waste  cocks  should  be 
substantially  made,  turned,  and  bored  in  a  workmanlike  manner, 
and  should  be  of  the  type  known  as  "  round  way."  The  mate- 
rials entering  into  their  composition  and  the  proportions  used 
at  Providence,  R.  I.,  are  as  follows:* 

80  Ibs.  copper; 
6  Ibs.  tin; 
3  Ibs.  zinc; 
2  Ibs.  lead. 

Mr.  William  R.  Hill  recommends  a  mixture  of  88  parts  refined 
copper,  6  parts  tin,  3  parts  zinc,  and  3  parts  lead  with  the  pro- 


FIG.  68. — Section  of  Inverted-key  Stop 
and  Waste  Cock. 


FIG.  69. — Compression  Stop 
and  Waste  Cock. 


viso  that  ' '  if  there  is  alkali  or  salt  in  the  soil  the  zinc  should  be 
omitted  on  account  of  corrosion."  Also  that  "  the  plugs  should 
be  lubricated  by  plumbago  and  Albany  grease  or  vaseline.  Bees- 
wax and  tallow  should  not  be  used,  as  it  will  get  hard  and  make 
it  difficult  to  open  or  close  the  valve."  f  One  objection  to  the 
ordinary  plug-cock  is  overcome  in  the  "inverted-key"  type. 


*  Jour.  N.  E.  Water-works  Assoc'n,  Vol.  XVIII,  p.  24. 

t/wa.,Voi.  xin,  PP.  37,38. 


254  MAINTENANCE  AND   OPERATION. 

The  plug  of  this  cock  is  inverted  and  the  pressure  upon  the  rod 
in  opening  or  closing  the  valve  tends  to  loosen  the  plug  and  facili- 
tate its  movement.  The  joint  is  kept  tight  by  the  pressure 
of  the  water  from  the  street  side,  a  by-pass  admitting  water 
under  pressure  to  the  under  side  of  the  plug.  The  stop  and 
waste  cock  at  the  curb  is  usually  provided  with  a  tee  handle, 
that  in  the  basement,  with  a  lever  handle.  A  compression  stop 
and  waste  cock,  somewhat  similar  in  appearance  and  operation 
to  an  ordinary  faucet,  has  been  recently  introduced  on  the  mar- 
ket, and  may  be  used  to  advantage  in  some  cases.  For  lead-pipe 
work  the  fittings  provided  with  union  joints  are  to  be  preferred, 
as  their  use  affords  a  means  of  ready  access  to  the  interior  of 
the  pipe  in  case  of  stoppages  caused  by  small  fish,  eels,  or  ice. 
The  joints  between  the  lead  pipe  and  fittings  may  be  made  in 
any  of  the  ways  mentioned  in  the  consideration  of  the  joint 
between  the  corporation  cock  and  the  gooseneck. 

The  fixtures  in  any  ordinary  residence  or  building  may  be 
adequately  supplied  by  a  service  connection  of  five-eighths  or 
three-quarters  of  an  inch  in  diameter,  but  hotels,  business  blocks, 
etc.,  often  require  services  of  larger  size. 

For  ordinary  service  connections,  pipes  of  wrought  iron,  which 
may  be  plain,  tarred,  galvanized,  or  lined  with  cement,  lead, 
or  tin,  and  of  lead  or  tin-lined  lead  are  in  common  use.  Services 
larger  than  two  inches  in  diameter  may  usually  be  more  eco- 
nomically laid  with  cast-iron  pipe.  The  three  classes  of  pipe 
first  mentioned  are  a  source  of  considerable  annoyance  and 
expense  in  many  systems,  as  some  waters  corrode  the  iron  with 
great  rapidity,  the  tar  or  galvanized  coatings  as  at  present  applied 
merely  postponing  this  action  in  a  measure.  As  a  result  of  the 
corrosive  action  the  pipes  are  quickly  filled  with  rust,  fixtures 
and  meters  clogged,  and  the  water  rendered  objectionable  for 
laundry  purposes. 

Cement-lined  iron  pipe  when  properly  lined  often  gives  entire 
satisfaction,  but  has  been  found  objectionable  in  some  cases 
owing  to  the  cracking  and  flaking  off  of  the  cement  and  the  diffi- 
culty in  obtaining  rust-proof  joints.  This  pipe  has  been  success- 
fully used  in  Brookline,  Massachusetts,  for  more  than  twenty-five 
years,  and  the  methods  used  in  its  lining  have  been  described  in 


SERVICE  CONNECTIONS.  255 

detail  by  Mr.  F.  F.  Forbes  in  a  paper  read  before  the  New  England 
Water-works  Association,  from  which  the  following  extracts  are 
taken:* 

' '  Our  departure  from  the  usual  custom  begins  with  the  buy- 
ing; we  specify  that  the  lengths  shall  be  about  16  feet  long 
and  also  of  standard  weight.  A  pipe  18  or  20  feet  long  cannot 
be  lined  with  the  same  degree  of  success  which  can  be  obtained 
with  pipes  somewhat  shorter;  and  our  experience  has  taught 
us  that  pipes  about  16  feet  long  give  the  best  results.  After  the 
pipes  are  delivered  at  our  shop,  we  first  straighten  all  which  are 
much  bent.  The  couplings  are  then  removed,  turned  around 
and  screwed  on  the  other  end,  in  order  that  there  may  be  no 
trouble  in  putting  the  lengths  together  when  lined.  The  pipes 
are  then  carefully  examined  in  order  to  make  sure  that  no  defect 
exists  in  the  welds  or  other  parts  of  them.  The  next  step  is  to 
run  a  cutting-tool  slightly  smaller  than  the  inside  diameter  of 
the  pipe  through  each  length  to  remove  all  dirt,  scales,  and  pro- 
jections of  iron  from  the  welds.  The  pipes  are  now  ready  for 
lining. 

"  No  sand  should  be  mixed  with  the  cement.  Portland  cement 
is  not  fit  for  this  work,  being  too  heavy  and  liable  to  fall  from 
the  sides  of  the  pipes  before  setting.  We  have  used  the  F.  O.  Nor- 
ton brand  with  great  success;  but  any  good  American  natural 
cement  which  does  not  set  too  rapidly  and  is  freshly  ground 
can  be  used  with  confidence.  It  is  very  necessary  to  sift  all 
the  cement  through  a  moderately  fine  sieve,  as  we  find  that  even 
the  best  cements  contain  small  pieces  of  unground  rock  and 
other  substances  which  interfere  seriously  with  the  lining.  It 
is  also  extremely  important  that  the  cement  should  be  used 
quickly  after  wetting.  When  lining  we  have  one  man  who  does 
nothing  but  mix  the  cement,  usually  preparing  enough  for  five 
or  six  pipes  at  one  time  and  constantly  working  it  over  to  keep 
it  at  the  right  thickness.  If  a  little  of  the  batch  is  left,  we  pre- 
fer to  throw  it  away  rather  than  to  mix  it  with  the  next  lot. 
The  press  used  for  filling  the  pipe  is  made  by  the  Union  Water 
Meter  Company,  of  Worcester,  Mass,  in  fact,  they  make  the 

*"  Cement-lined   Service-pipes."       F.    F.    Forbes,   Jour.    N.    E.  Water- 
works Assoc'n,  Vol.  XV. 


256  MAINTENANCE  AND   OPERATION. 

whole  outfit,  including  cones,  etc.  It  is  necessary  to  fill  the 
pipe  entirely  full  of  cement,  and  a  little  should  be  allowed  to 
run  out  of  the  farther  end.  More  of  the  cement  will  be  pushed 
out  by  the  cones,  but  this  can  be  returned  to  the  mixing-box 
and  used  again,  with  the  exception  of  that  from  the  last  pipe  filled 
from  the  batch,  which  is  thrown  away.  In  every  case  the  cones 
are  passed  through  the  pipes  twice.  A  handful  of  cement  is 
pushed  into  the  pipe  before  the  cone  enters  the  second  time, 
and  while  it  is  being  drawn  through,  the  pipe  is  slowly  revolved 
to  keep  the  cone  in  the  center  of  the  pipe.  We  endeavor  to 
keep  the  cones  as  near  the  center  of  the  pipe  as  possible;  we 
find,  however,  that  the  practical  results  are  the  same  if  the 
lining  is  quite  uneven.  The  cones  are  thoroughly  washed  after 
each  pipe  is  lined;  before  they  are  drawn  through,  a  piece  of 
pipe  from  12  to  18  inches  long  is  screwed  to  each  end  of  the  pipe 
to  be  lined,  so  that  the  lining  at  the  end  will  be  perfect.  After 
the  pipes  have  been  lined  from  three  to  five  days,  or  until  the 
cement  has  sufficiently  set,  a  thin  gruel  of  cement  is  run  through 
them.  This  is  done  by  elevating  one  end  of  the  pipe  and  pour- 
ing the  gruel  in  from  an  ordinary  watering-pot.  A  rubber  cone 
is  now  drawn  through,  which  leaves  the  inside  of  the  pipe  smooth 
and  quite  impervious  to  water.  The  ends  are  now  reamed  out 
to  fit  the  composition  ferrules  and  the  threads  cleaned.  This 
completes  the  process,  and  the  pipes  are  piled  away  for  use.  The 
number  of  feet  of  pipe  of  different  sizes  lined  and  grouted  by 
one  barrel  of  cement  is  as  follows: 

1  -inch  pipe 700  feet 

ij-   "        *    500     " 

2  -    "          "     300      " 

In  1898  the  cost  of  labor,  cement,  etc.,  for  lining  3000  feet  of 
2-inch  pipe  and  9000  feet  of  i-inch  pipe  was  as  follows: 

Labor  preparing  pipes $65 . 79 

"       cementing 66 . 65 

"       grouting 22 . 66 

"       reaming 39-98 

23  barrels  cement  @$i  .10 25 .30 

Coal  for  heating  shop 6.00 

$226.38 


SERVICE  CONNECTIONS.  257 

which  gives  the  cost  of  lining  2-inch  pipe  3.03  cents  per  foot,  and 
cost  of  lining  i-inch  pipe  1.5  cents  per  foot. 

"  Two  men  usually  get  the  pipe  ready  for  lining,  but  during  the 
process  of  lining,  six  men  are  found  to  be  the  most  economical 
number  to  use,  distributed  as  follows:  one  man  mixing  the  cement, 
one  man  filling  the  press  and  overseeing  the  work,  one  man  working 
the  press,  one  carrying  the  pipes  to  the  press  and  from  the  press 
to  the  coning-frames,  and  two  men,  one  at  each  end  of  the  pipe, 
doing  the  coning.  In  one  day  these  men  will  line  from  four  to 
five  thousand  feet  of  pipe. 

"A  few  words  describing  the  ferrules  we  use  at  all  joints.  These 
are  made  of  the  best  steam  metal,  five-eighths  of  an  inch  in  diam- 
eter on  the  inside,  the  outside  tapering  slightly  toward  the  end. 
They  are  of  two  kinds,  called  by  us  a  double  and  a  single  ferrule. 
The  double  ferrules  are  used  where  the  pipes  are  screwed  together, 
and  the  single  ferrules  where  the  pipes  are  screwed  into  the  side- 
walk stops  and  connections  at  the  main,  which  are  made  with  a 
shoulder  at  the  end  of  the  thread  to  hold  the  ferrules  in  place. 

"  It  has  often  been  stated  that  the  cement-lined  pipe  cannot  be 
bent  without  injury.  We  find,  however,  that  the  pipes  can  be 
bent  to  any  reasonable  extent,  without  any  damage  to  the  lining, 
if  this  is  done  with  care.  We  rarely  use  any  elbows  or  tees.  If 
we  have  to  use  a  turn  smaller  than  we  think  best  to  bend  the  pipe 
around,  we  use  a  short  piece  of  lead  pipe,  perhaps  a  foot  long,  with 
a  coupling  on  the  end,  and  in  making  the  connection  use  ferrules." 

Tin-lined  pipe  is  not  extensively  used  owing  to  its  cost,  but 
when  of  good  quality  it  possesses  an  advantage  over  other  service- 
pipes,  inasmuch  as  tin  is  rarely  affected  by  potable  waters. 

The  numerous  reported  cases  of  lead-poisoning  resulting  from 
the  use  of  water  drawn  from  lead  service- pipes  have  prejudiced  some 
consumers  against  them,  and  have  caused  water- works  officials  and 
others  to  doubt  the  advisability  of  the  use  of  pipes  of  this  material. 
Under  certain  conditions  such  use  may  endanger  the  health  of 
a  community,  and  it  would  be  advisable  to  enlist  the  services 
of  a  chemist  conversant  with  this  matter  before  the  adoption  of 
lead  as  the  material  for  the  service-pipes  of  a  system. 

Investigations  of  the  action  of  water  upon  lead  pipe  have  been 
made  in  Massachusetts  under  the  direction  of  the  State  Board  of 


258  MAINTENANCE  AND  OPERATION. 

Health,  the  results  of  which  appear  in  the  published  reports  of 
that  board.  The  results  of  these  investigations  indicate  that  the 
corrosive  action  of  the  potable  waters  of  Massachusetts  upon  lead 
is  due  principally  to  the  presence  in  the  water  of  comparatively 
large  amounts  of  carbonic  acid,  and,  in  a  measure,  oxygen;  the 
extent  to  which  the  dissolving  action  takes  place  being  dependent 
chiefly  upon  the  degree  of  hardness  of  the  water.  ' '  The  greater  the 
hardness  of  the  water,  as  compared  with  its  free  carbonic  acid,  the 
less  effect  did  the  carbonic  acid  have  upon  lead."  *  The  following 
extracts  from  the  published  reports  are  of  interest  in  this  connection. 

"Nearly  all  of  the  serious  cases  of  lead-poisoning  resulting 
from  the  use  of  water  taken  from  public  water-supplies  (in  Mas- 
sachusetts )  have  occurred  in  those  cities  and  towns  which  are  sup- 
plied with  ground-water;  but  surface-waters  also  act  upon  lead 
pipe,  and  though  the  quantity  found  in  surface-waters  drawn 
through  such  pipes  has  usually  been  small,  there  is,  nevertheless, 
danger  that  injury  to  health  may  result  even  if  the  water  is  drawn 
from  a  surface  source  if  lead  pipe  is  used  in  its  distribution."  f 

"A  water  which  ordinarily  acts  but  slightly  on  a  lead  pipe  may, 
by  some  change  in  conditions,  take  up  a  much  larger  quantity  of 
lead  than  under  ordinary  circumstances,  and  a  change  in  the  source 
of  the  supply  of  a  city  or  town  has  been  followed  by  a  material 
increase  in  the  action  of  the  water  upon  lead  service-pipes."  { 

"While  the  quantity  of  lead  dissolved  may  be  small,  and  a 
single  dose  might  not  seriously  harm  the  user  of  the  water,  the 
continued  use  of  water  containing  lead  is  harmful,  because  lead 
is  a  cumulative  poison.  The  exact  amount  of  lead  which  may 
be  taken  into  the  system  without  producing  harm  is  not  definitely 
known  and  may  vary  with  different  people,  but  it  is  known  that 
the  continuous  use  of  water  containing  quantities  of  lead  as  small 
as  .05  of  a  part  per  100,000,  or  about  ^  of  a  grain  per  gallon,  has 
caused  serious  injury  to  health."  § 

However,  since  many  potable  waters  do  not  attack  lead  seriously, 
and  in  the  case  of  some  soft  surface-waters,  the  presence  in  the 

*  Report  of  Mass.  State  Board  of  Health,  1900,  p.  488. 
t  Ibid.,  1 901,  p.  xxxi. 
%  Ibid.,  1901,  p.  xxxii. 
§  Ibid.,  1898,  p.  xxxii. 


SERVICE  CONNECTIONS.  259 

water  of  certain  mineral  matters  results  in  the  formation  of  coatings 
on  the  interior  of  the  pipe  which  serve  to  protect  the  metal,  pipes  of 
lead,  or  of  iron  lined  with  lead,  are  frequently  used.  As  a  measure 
of  precaution  in  any  case  where  lead  or  lead-lined  pipes  are  in  use, 
the  water  which  has  stood  in  the  pipes  overnight  or  for  any  con- 
siderable length  of  time  should  be  wasted. 

The  quantity  of  water  contained  in  service-pipes  may  be  com- 
puted with  the  aid  of  the  following  table. 

Internal  diam.  of  pipe  in  ins.      if         f          i         il        i|          2 
Contents  in  gallons  per  100 

feet  of  pipe 1.02   1.59  2.30  4.08  6.38  9.18   16.32 

The  service-boxes  in  general  use  are  of  the  telescopic  pattern 
and  usually  consist  of  three  parts:  a  base  or  lower  section,  an 
upper  section,  and  a  cover.  The  lower  section  is  enlarged  at  the 
bottom  in  order  that  the  curb-cock  may  be  partially  enclosed 
and  also  that  resistance  may  be  offered  to  the  lifting  action  of  frost. 
The  upper  section  either  slides  over  the  lower  or  is  connected  to 
it  by  a  threaded  joint.  One  objection  to  the  threaded  joint  is, 
that  in  some  soils  the  entire  box  is  lifted  by  frost  action  and  can- 
not easily  be  driven  back  into  place;  another  is  that  the  upper 
section  of  a  box  of  this  kind  is  more  liable  to  be  damaged  by 
teams.  Circular  covers  are  commonly  used,  but  boxes  set  in 
brick  walks  should  be  provided  with  square  or  rectangular  covers. 
The  top  of  the  box  or  cover  should  have  a  beveled  edge,  as  this 
offers  less  obstruction  to  passers-by.  The  cover  is  held  securely  in 
place  by  a  brass  screw-bolt  provided  with  a  triangular  or  pentagonal 
head,  as  loose  covers  or  covers  held  in  place  by  bolts  with  square 
or  hexagonal  heads  are  easily  removed  by  small  boys  and  other 
unauthorized  persons.  This  bolt  either  screws  into  the  top  section 
of  the  box  or  forms  a  part  of  a  special  clamp  designed  to  hold  the 
cover  in  place.  In  several  designs  for  service-boxes  another 
casting  is  added,  the  purpose  of  which  is  to  hold  the  stop-cock 
in  the  center  of  the  box  with  the  tee  head  in  a  vertical  position. 
Some  boxes  are  provided  with  a  short  rod  which  is  attached  to 
the  cock  and  held  in  the  center  of  the  box  by  lugs  on  the  interior 
of  the  casing.  Boxes  of  this  type  may  be  used  occasionally  to 
advantage  in  localities  where  the  ground-water  rises  in  a  soft 


260 


MAINTENANCE  AND  OPERATION. 


material,  with  the  result  that  the  bottom  of  the  box  is  often  partly 
filled  with  mud.  A  disadvantage  of  the  type  is  that  it  permits  of 
too  easy  access  to  the  shut-off  by  unauthorized  persons. 

As  a  general  rule,  the  service  connection  should  be  laid  at 


Buffalo. 


Stacy. 
FIG.  70. — Service-boxes. 


Chadbourne. 


right  angles  with  the  street-line  and  below  the  depth  ordinarily 
reached  by  frost.  It  should  enter  the  basement  of  the  building 
to  be  supplied  about  one  foot  below  the  level  of  the  floor,  as  this 
location  affords  better  opportunities  for  the  protection  of  the  pipe, 


SERVICE  CONNECTIONS.  261 

stop  and  waste  cock,  and  meter,  if  meters  are  used,  from  freezing. 
Where  pipes  are  brought  through  the  foundation  walls  above 
the  level  of  the  basement  floor,  freezing  is  liable  to  occur  on  the 
street  side  of  the  stop  and  waste  cock  when  the  water  is  shut 
off  at  night  in  houses  not  provided  with  heat  in  the  basement, 
and  in  others  when  the  building  is  unoccupied  temporarily,  and 
the  water  not  shut  off  at  the  curb.  When  lead  pipe  is  used  a 
small  arched  opening  should  be  left  in  the  wall  as  a  precaution 
against  injury  to  the  pipe  caused  by  settlement  or  sliding  of  the 
wall  stones.  The  location  of  the  consumer's  stop  and  waste 
cock  should  be  such  that  it  is  accessible  at  all  times,  and  in  no 
case  should  the  shut-off  be  placed  in  coal-bins,  ash-pits,  or  in 
places  where  it  may  be  covered  with  wood  or  rubbish.  The 
stop  and  waste  cock  at  the  curb  should  never  be  omitted,  as 
it  will  be  found  useful  in  the  enforcement  of  regulations  regard- 
ing non-payment  of  rates,  and  for  cutting  off  the  supply  from 
premises  which  are  vacant.  On  paved  streets  the  cock  should 
be  so  placed  that  the  service-box  will  be  in  the  sidewalk  next 
to  the  curbstone,  and  in  suburban  streets,  so  that  the  box  will 
be  located  in  the  grass  ground  between  the  gutter  and  the  walk, 
as  a  precaution  against  accidents  resulting  from  persons  tripping 
over  the  box  or  cover. 

The  water  should  be  turned  on  and  all  joints  tested  under 
pressure  before  the  trench  is  refilled,  as  the  water  escaping  from 
an  imperfect  joint  will,  especially  in  sandy  soil,  with  the  aid  of 
particles  of  earth,  rapidly  cut  away  the  pipe  or  fitting.  Many 
persons  object  to  the  use  of  one  trench  for  both  water  and  sewer 
connections  on  the  ground  that  leakage  from  the  service  con- 
nection may  enter  the  sewer  undetected.  However,  a  leak  of 
sufficient  size  to  be  detected  by  the  appearance  of  water  on  the 
surface  of  the  street  where  escape  into  a  sewer  is  impossible  will, 
if  such  escape  is  possible,  usually  make  its  presence  known  to 
a  water-taker  by  a  disagreeable  roaring  or  hissing  sound  from 
the  interior  piping.  Nevertheless,  in  cases  where  service-pipes 
have  previously  been  laid,  it  is  advisable  to  make  a  separate 
trench  for  the  sewer  connection  as  a  precaution  against  injury 
to  the  service  due  to  settlement,  particularly  when  the  sewers 
are  laid  by  contractors  or  individuals. 


262 


MAINTENANCE  AND  OPERATION. 


The  prices  of  materials  required  for  service  connections  depend 
upon  the  quantity  purchased,  its  quality,  and  the  discounts  from 
list  prices  in  force  at  the  time  purchases  are  made. 

Tapping-machines  including  drills  and  taps  for  ordinary  ser- 
vice work  cost  from  $60.00  to  $125.00. 

Corporation  and  stop  and  waste  cocks  when  purchased  in 
small  quantities  cost  about  as  follows: 


Style. 

Size. 

t" 

1" 

i" 

Corporation  cocks  with  coup- 
lings     

$ 

O  .  "?  5  tO  O.8^ 

$ 

o  .  80  to  1.05 

$ 

I  .  2O  to  I 

.60 

Ordinary  round-way  stop  and 
wastes  for  iron  pipe  

o  .  1  1  to  o  .  8  i 

0.85  to  i 

.  2  1 

Inverted  key  stop  and  wastes 
for  iron  pipe  

i  .  -}  c 

2.21 

Compression  stop  and  wastes 
for  iron  pipe  

i  .  40 

1.71 

Ordinary  round-way  stop  and 
wastes  for  lead  pipe  

o  .  60  to  0.75 

o  .  80  to  o.  90 

I  .  OO  to  I 

.  1O 

Ditto  with  union  joint 

O    71  to  O    OO 

i   oo  to  i    10 

i    25  to  i 

7  1 

Inverted  key  stop  and  wastes 
for  lead  pipe 

I    11 

i    3  1 

2    21 

Lead  flange  stop  and  wastes 
for  lead  pipe                .  .    . 

I  .  11 

i  .80 

2     OO 

Inverted  key  with  lead  flange 
connections. 

I  .  ncr 

2  .  2O 

7     t?O 

Compression  stop  and  wastes 
for  lead  pipe  

i  .  oo  to  1.15 

Service-boxes  cost  from  65  cents  to  $1.80. 

COST  OF  GALVANIZED-IRON  SERVICE-PIPE. 

Size,  inches f  i  ij  i£            2 

List  price  per  foot $o.n£  $0.16$  $0.22^  $0.27  $0.36 

(0.04  0.06  0.07^  0.09  0.12 

to  to  to  to           to 

0.05  0.07^  0.09  o.n  0.15 

COST  OF  LEAD-  AND  TIN-LINED  IRON  SERVICE-PIPE. 

Size,  inches f  i 

Lead-lined,  per  foot $0.14  $0.21 

Tin-lined,  per  foot o .  24  0.32 

The  cost  of  cement-lined  iron  pipe  is  about  as  follows  when 
made  by  the  department.  This  pipe  cannot  be  purchased  at 
present  from  dealers  in  service  supplies. 


SERVICE  CONNECTIONS. 


263 


Size. 
I    inch  lined  to    f  inch 


"      " 

4i      " 


Approximate  cost  per  foot. 
$o  .09 


o   12 
0,15 


2       "        "      "  if    "    ....................      0.18 

Lead  pipe  costs  from  5  to  5J  cents  per  pound. 
The  weight  per  foot  of   lead  pipe  is  governed  in  a  measure 
by  the  pressure  to  which  the  pipe  is  subjected,  and  also  by  the 


200 
150 

100 

90 

/ 

t 

1 
f 

t 

/ 

/       / 

i  --  ,  / 

T          7 

g 

'     I 

80 
70 
60 
50 

s,40 

F    *0 

/ 

,/ 

/ 

t 

/ 

/ 

/ 

i 

\    i    ]   •   i   •  i  /      r 

1 
-     t    -- 

:::::::jf  

::5i| 

0 

/ 
/ 

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i 

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tE~  

/            / 

rn  _     _  (_ 

s 

2j 

2 

/ 

v               , 

ptJ 

/ 

x->. 

/ 

^                2 

/ 

/ 

-v 

2 

./ 

/ 

/ 

/ 

s- 
c 

/ 

/ 

V 

/ 

c. 

2 

/ 

/ 

c 

y 

> 

h  ir, 

/ 

/ 

/ 

^/ 

i' 

/ 

C      9 

/ 

/ 

/ 

/ 

^ 

/ 

/ 

t 

r     ^ 

7 

a  J 

/ 

/ 

/ 

/ 

(v 

j 

« 

/ 

/ 

/~ 

/ 

S 
v2 

j 

« 

/ 

/ 

/ 

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^                  ? 

S! 

/     J 

/ 

/ 

/ 

/ 

1         y 

f    / 

f 

/ 

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V 

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f 
t 

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]_ 

. 

I 

}        4 

1 

" 

•  i 

1 

. 

0               30        40 

00   00    70  80  sKUOO 

150       2U 

Flow  in  Gallons  per  Minute 
FIG.  71. — Discharge  of  Service-pipes. 

standard  weights  supplied  by  the  manufacturers.     The  weights 
given  in  the  following  table  are  sufficient   for  ordinary  water- 
works purposes.    The  light  pipe  may  be  used  on  gravity  works 
under  a  low  head,  the  heavy  for  general  purposes. 
WEIGHTS  OF  LEAD  PIPE  PER  FOOT. 

Internal  diameter,  inches \        »         f         i         i$ 

Light,  pounds 2      i\        3        4        6 

Heavy,  pounds 3      3$        4i       6         9 


264  MAINTENANCE  AND  OPERATION. 

Solder  costs  from  20  to  25  cents  per  pound.  The  following 
quantities  are  usually  allowed  for  "wiped"  joints. 

Diameter  of  pipe,  inches J       f       f        i          i^ 

Pounds  of  solder f        i        i        i  i        if 

Very  little  solder  is  required  for  "  cup  "  joints. 

Tin-lined  lead  pipe  costs  from  gj  to  10  cents  per  pound. 

The  cost  of  the  labor  required  for  excavating,  back-filling,  and 
pipe-laying,  including  the  tapping  of  the  main,  averages  from 
10  to  25  cents  per  foot. 

It  is  seldom  necessary  to  make  any  computations  of  the  dis- 
charge of  service-pipes,  since  an  ample  supply  is  usually  furnished 
through  any  of  the  sizes  of  pipe  ordinarily  connected  to  a  sys- 
tem. Such  computations  are  sometimes  made  when  buildings 
are  located  at  a  distance  from  the  street-mains  and  at  an  ele- 
vation where  the  pressure  is  low.  Fig.  71  has  been  prepared  from 
the  figures  given  in  Weston's  Tables,  and  may  be  used  for  long 
lines  of  pipe  having  a  very  smooth  interior  surface  similar  to  lead. 


CHAPTER  IV. 

METERS. 

THE  meters  in  general  use  for  measuring  the  water  furnished 
consumers  are  of  the  positive  type.  Meters  of  this  type  measure 
and  automatically  record,  with  varying  degrees  of  accuracy,  the 
amount  of  water  which  has  passed  through  them,  and  are  divided 
into  several  classes,  known  as  reciprocating,  rotary,  oscillating, 
and  disc  piston  meters,  depending  upon  the  type  and  mode  of 
operation  of  the  piston  which  is  displaced  by  the  passage  of  the 
water.  Meters  of  the  first  class  are  provided  with  pistons  or 
plungers  which  operate  in  a  manner  somewhat  similar  to  those 
of  a  reciprocating  pump.  Those  of  the  second  class  are  pro- 
vided with  either  two  pistons  of  irregular  form  which  revolve 
about  fixed  centers  within  an  oval  chamber,  much  like  the  runners 
in  a  rotary  pump,  or  a  single-toothed  piston,  which  moves  in  a 
cylindrical  chamber,  the  interior  surface  of  which  is  provided 
with  a  number  of  projections  and  indentations.  In  the  latter 
case  the  piston  does  not  rotate  about  a  fixed  center  as  in  the 
previous  instance,  but  moves  in  such  manner  that  the  projections 
on  and  recesses  in  the  piston  and  walls  of  the  casing  form  a  series 
of  measuring-chambers.  In  meters  of  the  fourth  class  mentioned 
the  piston  has  a  disc  form  and  moves  with  an  oscillating  or  wab- 
bling motion,  in  its  movement  dividing  the  chamber  alternately 
into  receiving-  and  discharging-spaces.  A  radial  slot  cut  in  the 
disc  embraces  a  fixed  plate  or  wedge  set  vertically  within  the 
chamber  and  which  prevents  rotation  of  the  disc.  The  oscillating 
piston  meters  operate  in  a  somewhat  similar  manner. 

For  ordinary  purposes  the  pistons  or  discs  are  made  of  hard 
rubber,  which  in  some  makes  is  reinforced  with  metal.  Each 
complete  revolution  of  the  piston  or  disc  permits  the  passage 

265 


266 


MAINTENANCE  AND   OPERATION. 


through  the  meter  of  a  quantity  of  water  equal  to  the  contents 
of  a  chamber  or  series  of  chambers  of  known  capacity.  A  spindle 
attached  to  the  piston  or  disc  engages  a  train  of  gearing  by  which 
the  movement  of  the  piston  or  disc  is  transmitted  to  a  dial  or 
series  of  dials.  The  quantity  of  water  which  has  passed  through 
the  meter  is  thus  registered  upon  the  dials  in  either  cubic  feet 
or  gallons. 

The  smaller  meters  are  usually  provided  with  strainers  located 


FIG.  72. — f-inch  Union  Rotary  Piston  Meter. 

within  the  base  and  forming  a  part  of  the  meter.  Similar  strainers 
are  placed  in  some  of  the  larger  meters,  but  in  general  an  addi- 
tional fitting  known  as  a  fish-trap  is  set  in  connection  with  the 
meters  of  large  size.  Where  the  water  carries  considerable  grit 
in  suspension,  or  if  small  fish  are  often  present  in  the  pipes,  the 
use  of  an  independent  fish-trap  or  grit-chamber  is  often  advisable 
with  the  smaller  meters,  since  the  former  appliances  are  more 
readily  cleaned. 

The  type  of  meter  to  be  used  in  any  particular  case  depends 
to  a  considerable  extent  upon  local  conditions:    the  size  of  ser- 


METERS.  267 

vice,  amount  of  water  consumed,  pressure,  the  presence  of  sand, 
or  other  sediment  in  the  water  which  would  cause  excessive  wear 
of  the  casing  and  moving  parts,  the  accuracy  of  registration 
desired,  etc.  In  the  selection  of  a  meter  the  following  points 
should  be  given  consideration: 

1.  Accuracy. 

2.  Sensibility. 

3.  Durability. 

4.  Obstruction  to  flow. 

5.  Accessibility  of  working  parts. 

6.  Liability  of  stoppage. 

7.  Cost  of  repairs. 

8.  Extent  of  damage  as  a  result  of  freezing. 

9.  Capacity. 
10.  Cost. 

Service-meters  of  the  usual  size,  five-eighths  to  three-quarters 
of  an  inch,  when  new  should  not  over-register  more  than  one  per 
cent,  and  on  varying  rates  of  flow  should  register  approximately 
the  following  percentages  of  the  quantities  of  water  actually 
passed  through  them: 

Flow  in  cubic  feet  per  hour.  Per  cent  registered. 

0.5  50 

i  .o  90 

6.0  97 

15.0  to  maximum  capacity  98-99 

The  maximum  capacity  of  service-meters  is  given  by  the 
different  manufacturers  as  follows: 

Cubic  feet.  Gallons. 

Size  inches.  Per  minute.  Per  hour.  Per  minute.  Per  hour. 

I  2  120  15  900 

I  4  240  30  1800 

I  480  60  3600 

Where  the  detection  and  prevention  of  waste  are  of  importance, 
meters  should  be  tested  for  their  sensibility  to  STiall  rates  of  flow. 
This  factor  may  be  determined  by  testing  a  meter  under  a  flow 
just  sufficient  to  cause  registration  and  noting  the  quantity  passed 
and  the  percentage  registered  in  a  given  time.  In  many  cases 
this  sensibility  decreases  to  a  large  extent  with  use  and  tests 


268 


MAINTENANCE  AND  OPERATION. 


n> 

«  s? 


METERS. 


269 


of  this  nature  are  of  more  value  when  made  in  connection  with 
the  durability  test.  The  test  for  durability  is  made  by  passing 
through  the  meter  a  quantity  of  water  equivalent  to  the  consump- 
tion of  an  average  family  during  five  or  ten  years,  approximately 
100,000  cubic  feet,  after  which  the  meter  is  tested  for  accuracy 
and  sensibility.  This  test  is  usually  made  only  in  the  comparison 
of  meters  of  various  types  or  makes  as  a  guide  to  the  selection 
of  the  type  or  make  of  meter  best  adapted  for  use  on  the  works. 


FIG.  74. — Section  of  Worthington  Disc  Meter. 

The  obstruction  to  the  flow  of  water  through  a  service  con- 
nection due  to  the  introduction  of  a  meter  is  at  times  of  impor- 
tance, since  it  may  be  necessary  in  a  given  instance  to  use  a  meter 
of  larger  size  than  would  be  the  case  if  a  type  or  make  of  meter 
causing  a  less  loss  of  head  was  selected.  This  consideration  is 
of  particular  importance  where  meters  are  placed  in  pipes  which 
supply  water  to  motors  or  for  purposes  of  fire-protection.  The 
published  results  of  tests  made  by  Mr.  J.  W.  Hill,  C.  E.,*  of  twelve 
five-eighths-inch  meters  and  one  three-quarter-inch  meter  of  differ- 
ent makes,  and  by  Mr.  J.  Waldo  Smith,  C.  E.,f  of  six  five-eighths- 


*  Trans.  Am.  Soc.  C.  E.,  Vol.  XLI,  p.  407. 
^  Ibid.,  p.  377. 


270  MAINTENANCE  AND  OPERATION. 

inch  meters,  indicate  that  the  loss  of  head  caused  by  meters  of 
the  size  tested  is  about  as  follows: 

Flow  in  cubic  feet  Loss  of  head  in  pounds  per  square  inch. 

per  minute.  Tests  by  J.  W.  Hill.  Tests  by  J.  W.  Smith. 

20  13  to  30  8  to  33 

1.5  7  to  17  5toi8 

i  -o  4  to  13  2  to  8 

0.5  2  to  4  i  to  3 

The  meters  included  in  the  above  table  were  all  of  the  posi- 
tive displacement  type. 

As  a  general  rule,  the  size  of  meter  to  be  used  in  a  given  instance 
should  be  based  upon  the  amount  of  water  used,-  and  the  rate  of 


Cylinder,  with  piston.  Base. 

FIG.   75. — Cylinder,  Piston,  and  Base  of  AA  Empire  Meter. 

flow,  rather  than  upon  the  size  of  the  service  connection  in  which 
the  meter  is  to  be  placed.  A  f-inch  meter  will  usually  prove 
satisfactory  for  domestic  service.  For  this  purpose  meters  of 
the  disc  type  are  commonly  used  in  preference  to  those  of  the 
piston  pattern.  Aside  from  the  durability,  permanence  of  regis- 
tration, and  economy  in  first  cost  and  maintenance  of  disc  meters, 
meters  of  this  type  possess  a  peculiar  advantage  over  other  types 
as  a  leak-detector.  Mr.  Hill  *  found  that  a  noticeable  vibration 
of  the  discs  and  attached  spindle  in  the  meters  of  this  pattern 
tested  occurred  with  rates  of  flow  due  to  small  leaks  in  the  ser- 

*  Trans.  Am.  Sec.  C.  E  ,  Vol.  XLI,  p.  350. 


METERS 


271 


vice-pipe  and  fittings  which  were  not  sufficient  to    cause  regis- 
tration. 

The  following  prices  are  given  in  the  manufacturers'  lists: 

Disc 

.    $8.00 


;ttern. 
t. 


Size  of  meter. 

|  inch 

f     "    12  .  oo 

i        "    16 .  oo 

1  J  inches 30 .  oo 

2  "      50.00 


Piston  pattern. 
Cost. 


$IO.  OO  tO  $12  .OO 
15  .OO  "  21  .OO 
2O.OO  "  30.00 

40  .  oo   "     50  .  oo 

60.0O     "        65.00 


A  considerable  reduction  from  the  above  prices  may  usually 
be  obtained  when  large  numbers  of  meters  are  purchased. 


Round  reading  register.  Straight  reading  register. 

FIG.   76. — Meter-dials. 

Meters  should  be  tested  for  accuracy  before  being  placed  in 
service,  and,  where  meters  are  used  to  a  large  extent,  suitable 
testing  apparatus  should  be  provided  for  this  purpose.  An  inde- 
pendent supply-pipe  should  be  laid  from  the  street-main  to  the 
testing-room,  a  bench,  connecting  pipes,  and  fittings,  pressure- 
gages,  discharge-orifices  from  -fa  to  i  inch  diameter,  and  a  measur- 
ing-tank provided.  This  tank  may  be  calibrated  and  provided 
with  a  glass-tube  gage  with  a  scale  indicating  the  contents  of 
the  tank  corresponding  to  the  height  of  the  water  in  the  tube; 
or  the  tank  may  be  placed  upon  a  platform  scale,  the  water 
weighed,  and  the  contents  of  the  tank  in  cubic  feet  or  gallons 
computed  or  read  from  tables  prepared  for  that  purpose.  This 
latter  method  of  testing  is  that  generally  adopted. 


272  MAINTENANCE  AND  OPERATION. 

The  meter-testing  apparatus  of  the  Concord,  N.  H.,  water- 
works is  shown  by  the  accompanying  illustration.  The  Bureau 
of  Standards  at  Washington  has  recently  installed  a  meter-test- 
ing apparatus  consisting  of  a  bench,  a  Gow  meter-clamping  device, 
meter  support,  multiple-delivery  cock  with  twelve  orifices  from 
-g^-inch  to  2  inches  in  diameter,  a  tank  of  64  cubic  feet  capacity, 
and  a  5ooo-pound  Fairbanks  scale.  The  cost  of  the  equipment 
was  about  $350.00. 

The  Gow  clamping  device  and  the  various  patterns  of  multiple- 
delivery  cocks  are  almost  indispensable  in  cases  where  large  num- 


FIG.   77. — Meter-testing  Apparatus,  Concord,  N.  H.,  Water-works. 

bers  of  meters  are  tested,  owing  to  the  saving  in  time  effected 
by  their  use.  Where  but  few  meters  are  tested,  short  lengths 
of  rubber  hose  fitted  with  suitable  couplings  may  be  used  to 
connect  the  meter  with  the  piping.  The  rate  of  flow  may  be 
varied  by  orifices  drilled  in  brass  screw-plugs,  or  in  brass  caps 
which  are  placed  on  the  end  of  the  outlet-pipe,  or  thin  brass 
plates  may  be  drilled  and  set  in  unions  or  couplings.  A  tight 
cask  may  also  be  used  in  place  of  a  special  tank. 

The  orifices  for  the  regulation  of  the  discharge  should  be 
placed  on  the  outlet  side  of  the  meter,  and  the  water  should  be 
discharged  into  the  measuring-tank  at  an  elevation  somewhat 
higher  than  the  meter.  The  use  of  an  independent  supply-pipe 
for  the  meter-testing  apparatus  insures  a  more  uniform  pressure 
during  tests. 


METERS.  273 

Before  starting  a  meter  test,  water  should  be  allowed  to  pass 
through  the  meter  for  a  short  time  or  until  the  air  in  the  meter 
is  expelled  and  the  moving  parts  work  freely.  Care  should  be 
taken  to  turn  the  water  on  slowly,  otherwise  the  disc  or  registering 
mechanism  may  be  injured. 

The  meter  should  be  stopped  when  the  indicator  of  the  one- 
cubic-foot  dial  is  at  the  zero-point,  the  scale  balanced,  and  the 
weight  recorded.  The  flow  is  then  started,  time  noted,  and  5  to 
10  cubic  feet  passed  at  the  maximum  rate.  During  the  test  the 
readings  of  the  pressure-gages  on  the  inlet  and  outlet  sides  of 
the  meter  are  observed  and  the  loss  of  head  recorded.  The  flow 
should  be  stopped  when  the  indicator  of  the  one-cubic-foot  dial  is 
at  the  zero-point,  time  noted,  quantity  passed  noted,  and  weight 
observed.  The  method  of  procedure  is  similar  at  the  smaller 
rates  of  flow  except  that  a  smaller  quantity  of  water  is  passed 
through  the  meter.  During  tests  with  the  smallest  orifices  the 
meter  should  be  examined  for  leakage. 

For  convenience,  tables  should  be  prepared  which  show  the 
quantity  of  water  in  cubic  feet  corresponding  to  the  weight  of 
water  found  in  the  tank.  The  weight  of  a  cubic  foot  of  water 
varies  with  its  temperature,  but  for  ordinary  work  the  weight  is 
taken  as  62.5  Ibs.  In  some  works  the  tables  are  based  on  the 
weight  at  70°  F.  or  62.3  Ibs. 

WEIGHT  OF  ONE  CUBIC  FOOT  OF  WATER. 

Temperature.  Weight, 

degrees  Fahrenheit.  pounds. 

40  62.42 

45  62.42 

50  62.41 

55  62.39 

60  62.37 

65  62.34 

70  62.30 

75  62.26 

The  accuracy  of  the  meter,  or  the  percentage  of  the  actual 
amount  of  water  passed  which  is  registered  on  the  dials,  is  obtained 
b)'  the  following  formula: 

/Quantity  indicated  by  meter\ 

Percentage  registered  =  100  (  •      —^ — -r- — : -. ) . 

V  Quantity  in  tank          / 


274 


MAINTENANCE  AND  OPERATION. 


Data  with  regard  to  the  meters  tested,  the  details  of  the  tests 
made,  and  the  results  obtained  should  be  preserved  in  books 
or  on  cards  for  reference. 

In  setting  a  meter,  care  should  be  taken  that  the  meter  is 
secured  firmly  in  place  and  that  it  is  level.  Red  or  white  lead 
should  not  be  used  in  making  joints,  and  the  service-pipe  should 
be  flushed  before  the  meter  is  connected.  If  there  is  a  liability 


"toi  *•*-£?/.  &.&./..  ..... 


...£.» 

RESULT  OF  TEST  WHEN  NEW. 


Registered 
Actuel  Flow 


.4/7 


erp 
/Q 


SL 


FACE. 


REVERSE  SIDE. 


FIG.  78.  —  Card  for  Meter  Tests,  Baltimore  Water  Department. 
(Eng.  News,  vol.  XLVIII,  p.  357.) 

that  hot  water  may  reach  the  meter  from  the  interior  piping,  a 
check-valve  should  be  provided  near  the  outlet. 

Meters  are  placed  in  basements,  manholes,  or  boxes,  the  loca- 
tion and  method  of  protection  being  dependent  upon  local  con- 
ditions. The  meter  should  always  be  placed  on  the  house  side 
of  the  curb  stop  and  waste  cock,  and  valves  should  be  placed  on 
each  side  of  large  meters  in  order  that  they  may  be  accessible 
for  inspection  or  repair. 

Meters  placed  in  basements  are  enclosed  in  boxes  of  wood 
or  brick,  which  are  filled  with  sawdust,  mineral  wool,  or  other 
suitable  material  if  any  possibility  of  freezing  exists.  Meters 


METERS. 


275 


placed  outside  buildings  ate  set  in  manholes  or  boxes.  Large 
meters  should  be  enclosed  in  masonry  vaults  or  manholes  in 
order  that  the  meter,  fish-trap,  and  controlling-valves  may  be 
accessible  without  digging.  Service-meters  are  placed  in  large 
boxes  of  wood  provided  with  iron  covers,  one  or  more  lengths 
of  sewer-pipe,  or  a  light  cast-iron  box,  the  meter  being  set  near 
the  surface  in  order  that  the  dials  may  be  easily  read,  with  ver- 
tical inlet-  and  outlet-pipes  enclosed  within  the  box;  or  the 
meters  are  provided  with  dial  extensions  and  are  set  at  the  same 
grade  as  the  service  connections,  the  meter  and  dial  extension  being 


FIG.   79. — Manhole  Setting  for  Large  Meters. 


FIG.  80. — Volkhardt 
Meter -box. 


enclosed  in  a  small  iron  box  somewhat  similar  to  a  street  or  serv- 
ice-valve box.  The  use  of  dial  extensions  is  objectionable,  as  the 
friction  of  the  registering  mechanism  is  increased  and  the  sensi- 
bility of  the  meter  often  seriously  impaired  by  the  addition  of 
a  dial  extension. 

Large  numbers  of  service-meters  have  been  set  during  recent 
years  by  the  city  of  Cleveland  in  sewer-pipe,  the  method  of  setting 
at  present  in  use  being  shown  in  Fig.  81.  The  meter  is  protected 
from  frost  by  a  tight  cover  of  wood  treated  with  preservative 
chemicals,  which  is  placed  below  the  outside  iron  cover  to  pre- 
vent the  circulation  of  air  about  the  meter.  This  wood  cover 
consists  of  a  circular  rim,  which  is  calked  in  place  with  oakum, 
and  a  small  cover  which  is  opened  when  the  meter  is  read.  An 
extra  foot  of  sewer-pipe  is  used  where  the  danger  of  freezing 
requires  additional  precaution.  The  experience  with  meters 


276 


MAINTENANCE  AND  OPERATION. 


set  in  this  manner  during  the  unusually  severe  winters  of  1903 
and  1904  has  been  very  satisfactory. 


SECTION  A-B 
Standard  C.I. Manhole  and  Cover 


14&- 


Calked  with  Oakum  - 


h 

—if- 

ii 


•f  -H---J 

i 

a 

L 

_i     Cj 

J'.vi. 

FIG.  81. — Setting  for  Water-meters,  Cleveland,  Ohio. 

The  cost  of  setting  service-meters  in  basements  is  found  by 
different  water  departments  to  be  about  as  follows: 

Taunton,      Mass $2 . 50 

Watertown,     "    i .  oo 

Brookline,       c '     2 .  oo 

Springfield,      "     1.50  to  2.00 

Fitchburg,       "     i .  25 

Lawrence,        ' c     i .  25 

Wellesley,        "     i.oo 

The  cost  of  setting  f-inch  service-meters  in  Cleveland,  Ohio, 
during  1903  is  given  in  the  following  table:  * 


*  "The  Meter  System  in  Cleveland." 
Am.  Water-works  Assoc'n,  1904. 


Edward  W.  Bemis,  Proceedings  of 


METERS. 


277 


Basement 

settings. 

Brick  vaults. 

Sewer-pipe  settings. 

Brick.  . 

....    $O  .  I  2 

350  brick  

$2.45 

Sewer-pipe  $i  .  46 

Cement   .  . 

O    O  c; 

Cement   

o.  38 

Frost-cover  o  .  1  8 

Cover 

O    3O 

Iron      ring     and 

Iron    ring     and 

Fittings.  .  .  . 

O    2  Z 

cover  

7.21 

Fittings  

o.  «;o 

Pipe  and  fittings     0.55 

&0     72 

Labor 

....   90  .  7  2 

32  3 

Material 

$6.  <?4 

Material     .         $3  61 

Labor             .  . 

2  .  02 

Labor       .             4  01 

Total 

« 

.  .  .  .   *3  .  9  5 

Total 

$0    46 

Total        .       $7.62 

' '  During  the  year  1857  f -inch  meters  were  set  in  brick  vaults, 
3,174  in  basements,  and  9,378  in  sewer-pipe."  The  item  of  labor 
for  setting  in  brick  vaults  is  comparatively  low  per  meter,  since 
more  than  one  meter  was  often  set  in  a  single  vault. 

The  estimated  cost  of  setting  f-inch  meters  in  the  improved 
setting  in  1904  is  as  follows: 

Sewer-pipe $i .  84 

Frost-cover 0.47 

Cross-brace o .  04 

Ring  and  cover i  .42 

Pipe  and  fittings 0.55 


Labor 4.51 


Total $8.83 

Meters  on  domestic  services  are  read  quarterly,  and  those  on 
commercial  services  monthly,  in  many  works;  in  others,  all  meters 
are  read  once  a  month.  This  latter  method  is,  as  a  rule,  to  be 
preferred,  as  the  liability  of  loss  due  to  the  stoppage  of  a  meter 
or  the  breaking  of  any  of  the  parts  is  thereby  diminished.  When 
such  occurrences  take  place,  the  bill  may  be  adjusted  on  the 
basis  of  the  meter  registration  for  the  previous  period,  the  regis- 
tration for  the  period  after  the  meter  has  been  repaired  or  replaced, 
or  an  average  of  the  two. 

Whenever  a  decrease  in  the  amounts  registered  between 
meter  readings  is  noted,  unless  the  variation  can  be  satisfactorily 
accounted  for,  the  meter  should  be  removed  for  testing.  Service- 


278  MAINTENANCE  AND  OPERATION. 

meters  which  have  passed  from  three  to  five  hundred  thousand 
cubic  feet  of  water  usually  under-register  and  should  be  removed 
for  testing  and  repair.  Such  meters  are  often  repaired  by  changing 
the  gears  in  the  registering  apparatus.  If  the  piston  and  casing 
are  much  worn,  or  are  grooved  or  cut,  the  defective  parts  may 
be  made  smooth  and  the  casing  turned  down  in  a  lathe. 

Meters  will  often  pass  a  large  proportion  of  their  rated  capacity 
when  entirely  stopped.  Accumulations  of  rust  in  the  upper 
portion  of  the  casing  and  about  the  gear-train  interfere  with 
the  proper  operation  of  the  latter.  As  the  movement  of  the 
displacing  member  and  the  gears  are  usually  audible,  the  meter- 
readers  should  note  whether  the  meter  is  working  or  not  at  the 
times  readings  are  taken.  All  meters,  sediment-chambers,  and 
fish-traps  should  be  cleaned  at  intervals,  the  length  of  time  between 
cleanings  being  determined  from  local  experience. 

The  reading  of  the  meter-dials  is  at  times  rendered  difficult 
by  the  presence  of  moisture  on  the  under  side  of  the  dial-glass. 
This  condensation  may  be  often  prevented  by  placing  a  piece 
of  cloth  or  heavy  paper  between  the  lid  and  the  glass  cover,  or 
by  covering  the  dial-box  with  burlap. 

As  a  rule  the  boxes  containing  outside  meters  should  not 
be  opened  in  extremely  cold  weather. 

The  accuracy  of  service-meters  in  use  may  be  approximately 
determined  without  removing  the  meters  for  testing  by  a  method 
in  use  in  Newton,  Mass.*  The  occupants  of  a  house  supplied 
by  a  metered  service  having  been  notified  to  use  no  water, 
the  meter  is  read  by  an  inspector  and  I  cubic  foot  of  water 
passed  through  an  orifice  one-quarter  of  an  inch  in  diameter 
drilled  in  a  brass  cap  which  is  attached  to  a  convenient  faucet. 
The  water  is  caught  in  a  pail  of  known  capacity.  After  the 
required  quantity  has  been  drawn,  the  meter  is  again  read  and 
the  difference  between  the  registered  quantity  and  the  actual 
quantity  noted.  The  sensibility  of  the  meter  is  tested  by  running 
a  small  quantity  of  water  through  an  orifice  one-twentieth  of  an 
inch  in  diameter  drilled  in  a  second  cap.  Care  should  be  taken 


*  "  The  Care  of  a  Water-meter."    J.  C.  Whitney,  Jour.  N.  E.  Water-works 
Assoc'n,  Vol.  IX. 


METERS.  279 

that  during  the  tests  no  water  is  used  from  the  service  except 
through  the  faucet  to  which  the  caps  are  attached. 

The  cost  of  maintaining  service-meters  in  works  where  a 
large  proportion  of  the  services  are  metered  is  about  $1.00  per 
year  per  meter.  Interest,  sinking-,  or  depreciation-fund  charges 
are  not  included  in  the  above  amount.  This  sum  is  divided 
approximately  as  follows: 

Reading  and  inspection $0.30  per  meter  per  year. 

Repairs 0.45     "       " 

Office  expenses  (computing  and  mak- 
ing bills,  etc.) .     o .  25 


II  II 


Total $1.00    "      " 

In  metered  works  the  cost  of  reading  meters  is  from  2  to  3 
cents  per  meter  for  each  reading.  The  annual  cost  of  readings  is, 
therefore,  dependent  upon  the  number  of  readings  made  during 
a  year.  The  office  expenses  are  affected  by  the  number  of  bills 
rendered  each  consumer,  and  both  expenses  for  reading,  inspection, 
and  clerical  work  are  affected  by  the  efficiency  of  the  employes. 
The  average  cost  of  repairs  per  meter  is  dependent  upon  the 
number  of  meters  in  use  and  the  service  to  which  they  have  been 
subjected.  Where  meters  are  new  or  are  set  in  comparatively 
large  numbers,  the  average  cost  of  repairs,  obtained  by  dividing 
the  total  expenditure  for  repairs  by  the  number  of  meters  in 
service,  is  about  10  cents  per  meter  per  year  or  less.  In  works 
where  a  small  proportion  of  the  services  are  metered,  and  many 
of  the  meters  are  large,  the  average  cost  for  repairs  often  exceeds 
Si  .00  per  year. 


CHAPTER  V. 

CARE   OF   APPURTENANCES. 

A  REASONABLE  amount  of  care  should  be  exercised  by  the 
officials  and  employes  in  charge  of  a  system  of  water-works  to 
avoid  any  accident,  due  either  to  natural  causes  or  neglect,  which 
would  impair  the  efficiency  of  the  works  or  inconvenience  con- 
sumers. Under  favorable  conditions  the  amount  of  care  or 
oversight  may  be  comparatively  small,  but  usually  considerable 
vigilance  on  the  part  of  those  in  charge  is  required  at  times  to 
maintain  the  system  in  good  condition. 

Intakes  and  screens  should  be  kept  clean  and  free  from  obstruc- 
tion by  ice,  leaves,  dead  fish,  or  other  debris.  Ice,  especially 
in  the  form  of  anchor-  or  needle-ice,  is  occasionally  very  trouble- 
some and  often  interferes  seriously  with,  and  even  at  times  entirely 
prevents,  the  flow  of  water  into  the  intake-pipe.  Anchor-  and 
needle-ice  form  at  the  surface  of  the  water,  the  crystals  being 
drawn  down  to  the  intake,  to  which  they  adhere  in  large  masses, 
by  the  movement  of  the  water  toward  the  latter  when  the  water 
is  agitated  by  wind,  or  when  the  intake  is  located  in  a  flowing 
stream.  These  forms  of  ice  do  not  occur  when  the  surface  is 
frozen,  except  occasionally  in  streams  where  the  particles  are 
carried  under  surface-ice  from  open  water  by  the  current.  The 
tendency  is  for  needle-ice  to  accumulate  on  the  lee  shore.  Since 
this  ice  does  not  cause  trouble  in  still  water,  platforms,  rafts, 
or  log-booms  have  been  in  instances  moored  over  intakes  as  a 
means  of  protecting  the  latter.  As  methods  for  the  removal 
or  prevention  of  the  formation  of  this  ice  in  intake-pipes  and 
on  screens,  which  have  been  practiced  with  varying  degrees  of 
success,  may  be  mentioned  the  use  of  poles,  bars,  and  chains, 
steam,  or  hot  water  conveyed  through  pipes  if  the  distance  of 

280 


CARE  OF  APPURTENANCES.  281 

the  intake  from  the  shore  or  gate-house  admits  of  this  method, 
and  the  use  of  compressed  air.  The  discharge  of  warm  water 
from  the  condensing  apparatus  near  the  inlet,  and  the  reversal 
of  the  flow  in  the  intake-pipe  have  been  found  effective  in  some 
instances. 

In  a  system  supplied  by  pumps  but  not  provided  with  reser- 
voirs or  stand-pipes  having  a  comparatively  large  storage  capacity 
it  is  important  that  the  supply  of  water  should  be  uninterrupted, 
and  if  funds  are  available  reserve  machinery  should  be  installed 
in  the  pumping-station  for  emergency  use.  The  interest  charges 
on  such  additions  to  the  plant  will  usually  be  offset  by  the  saving 
due  to  the  increased  efficiency  and  decreased  depreciation  of 
the  machinery  in  daily  use,  owing  to  the  opportunity  afforded 
for  more  frequent  overhauling  and  repair  of  the  latter.  The 
friction  of  the  engine  and  pump  should  be  kept  at  a  minimum 
by  the  use  of  suitable  packing,  properly  placed,  and  good  oils. 
Air  in  the  pump,  due  to  either  leaks  in  the  suction-pipe  or  an 
excess  of  air  in  the  air-chamber,  causes  "pounding"  and  its  absence 
in  the  air-chamber  produces  a  like  result.  In  the  first  instance, 
occupants  of  houses  located  at  the  higher  elevations  are  annoyed 
by  the  presence,  of  air  in  the  service-pipes,  and  in  the  second 
the  pulsations  of  the  pump  give  rise  to  more  or  less  water-hammer. 
If  leaks  in  the  suction-piping  cannot  be  located  and  repaired 
the  air  may  be  removed  by  a  vacuum-pump  attached  to  a  drum. 
If  the  discharge-chamber  remains  full  of  water,  air  should  be 
forced  in  by  a  small  pump  until  a  sufficient  "cushion"  results. 

Sand  causes  cutting  and  excessive  wear  of  pump-plungers  and 
rings,  the  water-cylinder  linings  of  piston-pumps,  and  the  valves, 
and  should  be  prevented  from  entering  the  suction-pipe,  or  inter- 
cepted before  it  reaches  the  pump. 

The  amount  of  attention  given  to  the  boilers  and  engines 
is  dependent  in  large  measure  upon  the  character  of  the  employe 
in  charge,  and  the  position  of  engineer  should  be  filled  by  an 
experienced  and  conscientious  man.  However,  if  everything 
runs  smoothly  little  attention  is  often  given  to  the  slip  of  the 
pumps.  Although  the  installation  tests  and  duty  trials  of  a 
pum ping-engine  show  a  slip  of  but  from  i  to  3  per  cent,  and 
with  good  care  this  should  not  exceed  the  latter  figure,  instances 


282 


MAINTENANCE  AND   OPERATION. 


are  on  record  where  the  amount  of  slip  has  been  40  and  even  50 
per  cent  of  the  nominal  amount  of  water  pumped.  The  slip 
may  be  due  to  short-stroking,  loose  water-pistons,  worn  valves, 
or  a  combination  of  these  conditions,  and  tests  should  be  made 
from  time  to  time  for  its  determination.  In  the  absence  of  any 
measuring  device  for  gaging  the  quantity  of  water  delivered 
by  the  pump,  an  approximate  test  may  be  made  by  closing  a 
valve  in  the  discharge-main,  care  being  taken  that  this  shuts 
tight,  and  noting  the  number  of  strokes  or  revolutions  made 
by  the  engine  in  a  definite  time  both  before  and  after  closing 
the  valve. 

PUMP-SLIPPAGES  IN  A  NUMBER  OF  CITIES  AS  DETERMINED  BY 
PITOMETER  MEASUREMENTS. 

(Engineering  News,  Vol.  LII.  p.  538.) 


Capac- 
ity 
million 
gallons 
daily. 

City. 

Description. 

Per  cent 
ot  pump- 
age. 

10 

4 

I 
I 
6 

?l 

5 
5 
5 
5 

10 

i 

IO 

Norfolk,  Va  

So.  Bend,  Ind.  .  . 

<  i       «i          i  < 
<  i        <  <          <  « 

Oskaloosa,  la.  ... 
Columbus,  O.  .  .  . 

Cleveland,  O.  .  .  . 
«i           <  < 

New  York.  ..".'.'. 

Brooklyn  
Dayton    O    .  .    . 

High-duty,  inside-packed  

4.2 

iz.  9 

57-° 
20.  o 
24.0 
19.0 
30.0 
33-° 
33  -o 

12.0 
10.  I 

55-0 
25.0 

i-5 

Power-driven,  inside-packed  

valves  newly  overhauled  .  .  . 
Duplex  inside-packed 

Comp.  ring  and  plunger  

Ring  and  plunger,  inc.  jet  condenser.  .  .  . 
Inside-packed 

Vertical  triple,  inside-packed  (valves  were 
adrift) 

Well-pumping  station 

New  vertical  triple,  single-acting  plung- 
ers, outside-packed  

The  principal  factor  by  which  the  comparative  efficiency  of  the 
pumping-plant  may  be  determined  year  by  year  is  the  cost  of  lift- 
ing a  stated  quantity  of  water  a  definite  height.  The  units  in 
general  use  for  this  purpose  are  1,000,000  gallons  and  i  foot 
respectively.  As  the  cost  of  supplies  and  repairs  is  usually  a 
small  proportion  of  the  annual  expenditures  for  operation,  and 
the  salaries  of  the  employes  practically  fixed  in  amount,  the  unit 
cost  mentioned  is  dependent  chiefly  upon  the  amount  and  cost 


CARE   OF  APPURTENANCES. 


283 


of  the  coal  consumed.  Hence  care  and  good  ]udgment  should 
be  exercised  in  the  purchase  and  use  of  the  fuel-supply.  The  com- 
parisons mentioned  cannot  be  made  unless  sufficient  data  are 
recorded  daily  and  preserved  for  reference  in  form  similar  to  that 
outlined  in  Chapter  I. 

The  unit  cost  of  pumping  varies  within  wide  limits  and  is 
affected  by  many  conditions,  as  size  and  efficiency  of  plant, 
quantity  pumped,  total  head,  average  daily  duration  of  pumping, 
cost  of  coal,  character  of  labor,  etc.,  similar  conditions  rarely 
obtaining  in  any  two  localities,  but  the  statistics  given  in  the 
following  table  may  be  found  to  be  of  interest. 

COST  OF  PUMPING  IN  VARIOUS  LOCALITIES. 

(From  Jour.  N.  E.  Water-works  Assoc'n,  Vol.  XIX.  1905.) 


City  or  town. 

Total 
pumpage 
for  year  in 
millions  of 
gallons. 

Average 
dynamic 
head  in  feet. 

Duty 
in  million 
foot-pounds 
per  100  Ibs. 
of  coal. 

Cost  per 
million 
gallons 
raised 
one  foot. 

Oberlin,  Ohio  

7  3 

84 

1  1 

$o.3< 

Bay  City,  Mich  

I   OQI 

IJ7 

21 

0.071 

Reading,  Mass   

$6 

24O 

24 

o  .  260 

Middleboro,  Mass  

Q-J 

2O4 

2  S 

o  .  14 

Billerica,  Mass  

?7 

316 

3O 

0.171 

Atlantic  City,  N.  J  

I  ,627 

126 

•2T 

o  ,  087 

Westerly,  R.  I  

2  SI 

2IO 

31 

o  .  1  08 

Ware,  Mass   

128 

244 

4° 

o  .  100 

Marlboro   Mass 

221 

173 

4  3 

O    O77 

Newton   Mass 

800 

2  S7 

4.7 

O    OS 

\Vobiirn    Mass 

C2O 

214, 

47 

o  074. 

Woonsocket   R    I 

4.OO 

24.O 

4.8 

O.  OS7 

Cleveland,  Ohio  
Lawrence   Mass      ...       \ 

22,535 
78 

2I9 
318 

61 
86 

0.025 
0.096 

Waltham    Mass   

949 

7  SO 

185 

180 

70 
07 

O.O/I 

o   OSQ 

Cambridge   Mass  

2831 

194 

131 

O  .  O"}  I 

Metropolitan     Water-! 
works    Mass                       i 

576 

293 
10,523 

121 

128 
129 

65 
121 

135 

0.059 

°-°35 

O.O22 

I 

20,269 
2,927 

55 
129 

110 

132 

0.030 
0.031 

Stand-pipes  should  be  examined  at  intervals,  leaks  in  joints 
remedied  by  calking,  and  bolts  or  rivets  which  have  been  loosened 
by  the  movement  of  ice  in  the  interior  of  the  tank  or  from  other 
causes  tightened.  The  interior  of  the  stand-pipe  should  be  painted 
at  intervals  of  two  or  three  years,  or  as  local  conditions  may  require, 


284  MAINTENANCE  AND  OPERATION- 

a  durable  paint  of  good  quality  being  used  for  that  purpose. 
The  metal  should  be  clean  and  free  from  loose  scale  before  the 
paint  is  applied.  Cleaning  by  aid  of  a  sand-blast  is  the  most 
effective  method  of  treatment,  but  is  usually  not  resorted  to  on 
account  of  the  cost.  The  scale  and  rust  may  be  removed  by 
steel  scrapers — articles  made  from  flat  files  or  old  saw-blades 
ground  on  one  edge  and  set  in  a  suitable  handle  have  given 
satisfaction — after  which  the  metal  should  be  thoroughly  brushed 
with  steel  brushes.  The  exterior  of  the  stand-pipe  does  not 
usually  require  repainting  as  often  as  the  interior,  and  paint  of  a 
somewhat  cheaper  grade  may  be  used. 

All  public  fire-hydrants  connected  with  the  works  should  be 
inspected  at  least  twice  yearly:  once  in  the  autumn  before  cold 
weather  sets  in,  and  again  in  the  spring.  At  these  inspections  the 
hydrants  should  be  oiled  and  the  threads  of  the  nozzles  and  caps 
lubricated.  In  cold  climates  the  fall  inspection  is  of  the  utmost 
importance,  as  the  value  of  the  system  for  fire-protection  depends 
upon  the  condition  of  the  hydrants,  and  considerable  loss  may  be 
incurred  if  these  appliances  are  out  of  order  or  frozen.  A  hydrant 
may  be  rendered  temporarily  useless  in  cold  weather  by  the  freezing 
of  water  in  the  barrel.  The  water  may  come  from  the  mains 
through  a  leaky  valve,  or  surface  water  may  find  its  way  into  the 
space  between. a  hydrant  and  the  frost-case  and  enter  the  drip,  or 
water  may  remain  in  a  hydrant  after  use  owing  to  an  ob- 
structed drip.  In  the  first  instance  the  leakage  may  be  due 
to  a  cut  or  worn  valve,  or  a  sprung  rod,  and  when  such  leakage 
is  apparent  the  defective  part  should  be  repaired  or  renewed 
at  once.  In  the  second  instance  the  drip  should  be  plugged  and 
the  hydrant  pumped  dry  after  use.  A  hydrant  in  which  the  drip 
is  obstructed  by  tree-roots,  rust,  pebbles,  or  other  matter  will 
drain  very  slowly,  if  at  all,  and  the  fall  of  the  water  in  the  barrel 
when  the  hydrant  is  closed  should  be  observed  at  the  time  of 
inspection.  Tree-roots  are  very  troublesome,  as  the  cutting  away 
of  the  roots  merely  postpones  the  time  when  the  drip  will  be  again 
closed  until  a  new  growth  is  made.  The  better  way  to  deal  with 
cases  of  this  nature  is  to  connect  the  drip  with  the  street  sewer  by 
a  service-pipe,  the  street  surface-water  drains  usually  being  laid 
above  the  level  of  the  bottom  of  the  hydrant.  Accumulations  of 


CARE  OF  APPURTENANCES. 


285 


rust  and  earth  in  the  drip  may  be  removed  by  the  admission  of 
water  to  the  hydrant  alter  the  nozzle-caps  have  been  made  air- 
tight, after  which  the  main  valve  is  closed,  when  the  escape  of 
the  water  under  the  pressure  due  to  the  compressed  air  in  the  top 
of  the  barrel  scours  the  waste-opening  clean. 

The  consensus  of  opinion  among  water-works  superintendents 
is  that  the  main  valve  of  a  hydrant  should  not  be  opened  between 
the  fall  and  spring  inspections  except  in  case  of  fire.  In  very  cold 
weather  the  hydrants  should  be  examined  at  intervals  for  the 
presence  of  ice  or  water  in  the  barrel  above  the  valve  or  drip  by 


TOOL  FOR  TESTING  FIRE  HYDRANTS 


FIG.  82. 


the  use  of  a  flexible  rod — an  old  whip  answering  this  purpose — or 
a  metal  ball  attached  to  a  cord.  The  device  shown  in  Fig.  82  *  has 
been  used  with  success  at  Reading,  Pa.,  for  this  purpose.  A  knot 
or  marker  on  the  cord  which  supports  the  weight  indicates  the 
depth  of  the  barrel,  the  different  depths  of  the  several  makes  of 
hydrants  being  indicated  by  marks  on  the  handle. 

Doubtful  hydrants  may  be  given  a  dose  of  wood-alcohol  or 
salt,  but  the  continuous  use  of  the  latter  is  objectionable  owing 
to  its  corrosive  action. 

Hydrants  which  have  been  used  for  fire  or  other  purposes 
during  the  winter  months  should  be  examined  after  such  use. 

Nozzle-caps  should  never  be  left  loose,  as  mischievous  boys 
often  take  advantage  of  the  opportunity  thus  offered  and  place 


*  E.  L.  Nuebling,  "  A  Simple  Device  for  Testing  Fire-hydrants,"  Proceed- 
ings Am.  Water -works  Assoc'n,  1903. 


286  MAINTENANCE  AND  OPERATION. 

stones  and  sticks  in  the  barrel.  These  may  be  washed  out  through 
the  steamer-nozzle,  or  the  top  of  the  hydrant  if  the  cap  is  re- 
moved, or  if  these  methods  fail,  tongs  or  hooks  may  be  used  to 
remove  the  obstructions. 

The  indiscriminate  use  of  hydrants  by  employes  of  street 
or  sewer  departments,  contractors,  or  private  individuals,  or  for 
the  filling  of  street-sprinkling  carts  should  never  be  permitted. 
In  the  former  cases  the  hydrant  should  be  opened  and  closed 
by  an  employe  of  the  water  department,  or  if  the  water  is  to 
be  used  for  some  time  an  ordinary  wheel-valve,  with  or  without  a 
reducing  coupling,  should  be  placed  on  one  nozzle  and  the  hydrant 
opened  in  the  morning  and  closed  at  night  by  a  competent  man. 
Sprinkling-carts  should  be  filled  from  stand-pipes  or  water-cranes 
provided  for  that  purpose. 

The  nuts  securing  the  valves  of  plug-hydrants  to  the  rod  should 
not  be  allowed  to  become  loose,  or  if  the  valve  is  not  held  firm, 
washers  should  be  added,  as  water-hammer  will  result  from  the 
closing  of  such  hydrants  if  the  valve  seats  with  the  pressure. 

Valves  and  hydrants  should  be  operated  at  a  slow  rate  in 
order  that  water-hammer  may  not  be  produced.  When  water 
is  turned  on  a  main  which  has  been  drained  for  any  purpose, 
one  or  more  hydrants  located  at  dead  ends  and  summits  should 
be  opened  to  allow  the  air  contained  in  the  pipe-line  to  escape. 
Air  should  be  admitted  to  the  interior  of  a  long  pipe-line  near 
the  controlling  valve  when  the  pipe  is  drained  in  cases  where 
the  valve  is  located  at  a  higher  elevation  than  the  outlet.  Dis- 
regard of  this  precaution  has  at  times  resulted  in  injury  to  or 
destruction  of  the  valve,  or  of  portions  of  the  main  below.  This 
effect  has  been  accounted  for  by  the  theory  that,  as  a  result 
of  the  vacuum  produced  in  the  main  between  the  valve  and  the 
receding  column  of  water,  a  portion  of  the  latter  is  detached 
and  returns  with  considerable  momentum,  the  force  of  impact 
being  sufficient  to  break  the  valve  or  main.* 

The  valves  of  a  system  should  be  examined  occasionally,  and 
leaking  stuffing-boxes  made  tight  by  a  renewal  of  the  packing 
about  the  valve-stem.  Packing  lubricated  with  oil  and  plum- 

*  Jour.  N.  E.  Water-works  Assoc'n,  Vol.  XVI,  p.  136. 


CARE  OF  APPURTENANCES.  287 

bago  is  suitable  for  this  purpose.  Care  should  be  taken  in  the 
operation  of  a  valve  that  the  disc  or  discs  are  not  wedged,  as 
stripping  of  the  threads  or  breaking  of  the  valve-stem  is  easily 
accomplished  in  this  case.  After  opening,  a  valve  should  not 
be  left  with  the  wedge  set  tight,  but  the  gate- wrench  should  be 
turned  in  a  reverse  direction  a  few  times  in  order  that  the  disc 
may  be  left  loose. 

Valves  on  circuit  lines  should  be  examined  frequently,  espe- 
cially after  they  have  been  closed  for  repair  or  other  work,  as 
such  valves  are  often  left  closed  by  careless  workmen,  no  indi- 
cation being  given  that  such  is  the  case,  as  would  result  when 
the  line  is  controlled  by  a  single  valve. 

The  tops  of  street-  and  service-boxes  should  be  maintained 
flush  with  the  surface  of  the  ground  or  pavement.  If  the  boxes 
are  lifted  by  frost  action,  they  may,  if  of  the  telescopic  pattern, 
be  driven  down  into  place  with  a  wooden  maul.  Hot  water 
poured  into  the  box  will  soften  the  ground  and  prove  of  ser- 
vice in  obstinate  cases. 

As  is  the  case  with  hydrants,  valve-boxes  are  often  made 
receptacles  for  sticks,  stones,  and  other  rubbish  when  located 
in  unfrequented  places  and  alleys.  Tongs,  hooks,  scoops,  and 
other  contrivances  may  be  used  to  clear  the  box  hi  these  cases. 
A  circular  mirror  about  3  inches  in  diameter  will  be  found  very 
useful  in  locating  obstructions  in  the  box,  as  the  sunlight  can 
be  reflected  into  the  box  by  the  mirror,  thus  lighting  the  interior. 
The  mirror  will  also  be  found  useful  in  locating  the  tee  head  of  a 
curb-cock,  and  by  its  use  the  wrench  may  be  placed  directly 
on  the  handle  of  the  shut-off.  Without  the  mirror  more  or  less 
time  is  lost  in  fitting  the  wrench  in  place,  and  often  the  shut-off 
is  struck  and  turned  to  one  side. 

The  space  between  the  valve-box  and  its  cover  is  often  filled 
with  ice,  and  the  entire  cover  at  times  is  covered  by  this  sub- 
stance. Benzine  or  gasolene  placed  in  a  cup-shaped  depression 
cut  in  the  ice  over  the  cover  will  on  ignition  melt  the  ice  and 
loosen  the  cover.  A  handful  of  waste  soaked  with  kerosene 
will  accomplish  a  like  end.  When  but  little  snow  is  upon  the 
surface  of  the  street,  frequent  applications  of  salt  to  the  covers 
will  tend  to  keep  them  clear. 


288  MAINTENANCE  AND   OPERATION. 

The  flow  of  water  through  service  connections  is  often 
obstructed,  entirely  or  in  part,  by  the  presence  of  small  fish 
or  eels  in  the  corporation  cock  or  service-pipe.  If  the  fish  or 
eel  has  not  passed  the  corporation  cock,  the  service-pipe  may 
be  disconnected  in  the  basement  of  the  building  at  the  shut-off, 
a  small  force-pump  attached,  and  sufficient  pressure  applied  to 
force  the  obstacle  out  into  the  main.  At  the  same  time  a  hydrant 
or  blow-off  located  on  the  main  beyond  the  service  in  question 
should  be  opened.  Obstructions  of  this  nature  between  the 
corporation  cock  and  the  building  may  be  removed  by  inserting 
a  stiff  wire,  looped  at  the  forward  end,  into  the  service-pipe  from 
the  basement.  The  material  is  broken  up  by  the  wire  and  brought 
out  by  the  water.  A  wire  of  this  kind  will  also  be  found  useful 
in  cleaning  pipes  which  are  clogged  with  rust.  The  looped  wire 
should  be  pushed  into  the  service-pipe  against  the  pressure  and 
the  material  loosened.  The  detached  particles,  and  masses  of 
rust,  will  be  washed  out  by  the  running  water,  and  the  service- 
pipes  should  not  be  connected  up  again  until  the  water  runs 
clear,  otherwise  the  fragments  will  lodge  in  faucets  or  ball-cocks 
and  cause  trouble. 

The  closing  of  the  inlet  of  the  corporation  cock  as  the  result 
of  tuberculation  of  the  main  at  this  point  may  be  remedied  by 
excavating  to  the  former,  disconnecting  the  gooseneck,  and 
drilling  out  the  opening.  If  the  corporation  cock,  when  first 
placed,  projects  into  the  main  one-half  to  three-quarters  of 
an  inch,  little  trouble  should  be  experienced  from  obstructions 
due  to  the  above  cause.  The  decrease  in  the  flow  of  water 
due  to  obstruction  of  the  connection  by  rust  will,  unlike 
that  due  to  the  presence  of  eels  or  fish,  usually  be  very 
gradual. 

More  or  less  sediment,  even  with  apparently  clear  waters,  is 
deposited  in  the  main  pipes  of  a  system,  and  the  capacity  of 
the  mains  is  often  decreased  by  the  formation  of  growths  or 
incrustations  upon  the  interior.  The  sediment  should  be  removed 
by  increasing  the  velocity  of  flow  through  the  pipes,  and  this 
may  be  accomplished  by  the  discharge  of  water  from  fire-hydrants 
and  blow-offs.  When  a  main  is  shut  off  and  drained  for  any 
purpose  the  water  which  first  enters  when  it  is  again  placed  in 


CARE  OF  APPURTENANCES.  289 

service  should  be  wasted  in  this  manner,  or  complaints  that  the 
water  is  dirty  will  be  received  from  consumers. 

The  presence  of  incrustations  upon  the  interior  of  cast-iron 
pipes,  or  of  growths  of  pipe-moss  or  fresh-water  sponge  upon 
pipes  and  conduits  causes  a  reduction  in  the  delivering  capacity 
of  the  main  affected  by  such  growths.  This  reduction  is  due 
to  the  contraction  of  area  of  the  pipe  or  conduit,  to  the  retarda- 
tion caused  by  the  increased  frictional  resistance  offered  to  the 
flow,  and  to  the  production  of  eddies.  The  formation  of  incrusta- 
tions and  growths  is  dependent  upon  the  character  of  the  water 
and  the  condition  of  the  interior  surface  of  the  pipe.  Incrusta- 
tion does  not  occur  with  some  waters,  but  in  other  cases  the 
coatings,  as  at  present  applied  to  commercial  pipe,  do  not  entirely 
prevent  the  formation  of  tubercules.  The  tubercules  vary  in 
size  and  appearance,  the  smaller  presenting  an  appearance  not 
unlike  a  blister,  the  larger  resembling  cones  of  varied  form. 
These  are  usually  hollow  or  contain  a  soft  spongy  mass  of  rust 
and  other  matter,  and  when  first  removed  from  a  pipe  the  out- 
side is  quite  hard,  but  after  exposure  to  the  air  for  some  time 
the  mass  often  crumbles  and  may  be  easily  crushed  by  the  hand. 

Tubercules  or  other  growths  may  be  removed  by  scrapers  or 
brushes  drawn  through  the  pipes  by  hand  or  forced  through  by 
water-pressure.  Several  devices  have  been  used  with  success  for 
this  purpose  in  Great  Britain  and  its  dependencies,  but,  with  the 
exception  of  a  few  experimental  trials,  the  method  of  scraping 
has  not  been  introduced  in  any  water-works  systems  in  the 
United  States.  The  scrapers  used  consist  of  a  central  shaft  to 
which  are  attached  steel  cutting-blades  or  knives,  and  pistons  of 
rubber,  leather,  wood,  metal,  or  a  combination  of  these  materials. 
The  shaft  and  cutting-blades  are  usually  flexible,  or  the  latter  are 
held  in  place  against  the  pipe  by  springs,  in  order  that  the  appara- 
tus may  pass  slight  obstructions  which  cannot  be  removed,  and 
around  curves  of  thirty  or  more  feet  in  radius.  The  hand-scrapers 
are  little  used  except  for  cleaning  short  sections,  as  their  use 
necessitates  frequent  cutting  of  the  main.  The  automatic  scrapers 
are  introduced  into  the  pipe  through  openings  cut  in  the  latter, 
or  hatch-boxes  designed  for  the  purpose,  and  when  in  place  are 
forced  through  the  main  by  the  pressure  of  the  water  behind  them, 


290  MAINTENANCE  AND  OPERATION 

the  course  of  the  apparatus  through  the  pipe  being  noted  by 
observers  on  the  surface,  as  the  noise  due  to  the  action  of  the 
device  is  noticeable  above  ground. 

The  results  obtained  by  the  use  of  these  scrapers  have  been  very 
satisfactory  as  regards  the  increase  in  the  discharge  of  the  pipes 
cleaned,  since  the  delivering  capacity  of  the  main  so  treated  has 
been  increased  from  25  to  100  per  cent  in  several  instances. 
This  increase  in  capacity  is,  however,  not  permanent,  as  the  in- 
crustations removed  are  soon  replaced  by  a  new  growth.  In 
order  that  the  method  may  be  of  value  the  pipes  must  be  scraped 
at  frequent  intervals,  and  hatch-boxes  are  set  permanently  in 
place  at  convenient  points  to  facilitate  the  operation. 

The  cost  of  the  work  is  dependent  upon  the  age  of  the  main 
and  the  amount  and  character  of  the  incrustation  within  it,  the 
cost  of  rescraping  being  usually  much  less  than  the  first  cost  of 
cleaning. 

The  original  cost  of  cleaning  4.3  miles  of  24-inch  supply- 
main  at  St.  John,  N.  B.,  in  1897-98  was  about  $64.00  per  mile,  or 
12  cents  per  foot.  The  scraper  used  (Fig.  83)  cost  about  $40.00 
and  a  distance  of  about  94.5  miles  was  covered  to  accomplish  the 
work.* 

In  1886-87  58,000  feet  of  6-inch  and  20,300  feet  of  12-inch 
distribution  mains  were  cleaned  at  Boston,  Mass.,  at  a  cost  of  14 
cents  and  20.6  cents  per  foot  respectively,  the  costs  including  a 
royalty  payment  of  5  cents  per  foot  for  the  right  to  use  the 
scraper.f 

The  supply-mains  at  Torquay,  England,  are  scraped  every 
year  at  a  cost  of  about  $3.50  per  mile  for  labor.  The  mains  are 
9  and  10  inches  in  diameter  and  the  scraper  used  cost  about 
$112.00. { 

At  Melbourne,  Australia,  the  first  cost  of  cleaning  about  164 
miles  of  pipe  from  4  to  12  inches  in  diameter  from  1897  to  1902 
varied  from  about  $10.00  to  $120.00  per  mile  of  main  cleaned. 

*  "Cleaning  a  Water-main  in  St.  John,  N.  B."  Wm.  Murdoch,  Jour. 
N.  E.  Water- works  Assoc'n,  Vol.  XIII. 

t  Discussion  of  above  paper  by  Dexter  Brackett. 

%  ' '  English  Practice  in  Cleaning  Water-mains  with  Scrapers  and  Brushes," 
Eng.  News,  Vol.  XLIV,  p.  154. 


292 


MAINTENANCE  AND   OPERATION. 


The  scrapers  used  cost  from  about  $60.00  for  the  4-inch  size  to 
$325.00  for  the  12-inch  size.* 

At  Halifax,  N.  S.,  in  1898,  112,803  feet  of  water-pipe  from 
3  to  24  inches  in  diameter  were  recleaned  at  an  average  cost 
of  about  $20.00  per  mile.f 

The  above  method  of  increasing  the  delivery  of  pipes  should 
be  found  of  value  in  the  case  of  small  cast-iron  supply-mains,  the 
capacity  of  which  has  been  impaired  by  the  presence  of  incrusta- 
tions. 

The  flow  of  water  through  supply-  or  force-mains  which  are 
not  tapped  for  service  connections  or  hydrants  is  at  times  ob- 
d 


FIG.  84. — Air-valve. 


structed  by  accumulations  of  air  at  high  points  or  summits  along 
the  main,  and  automatic  air-valves  are  used  to  allow  such  accumu- 
lations to  escape  from  the  pipes.  These  devices  usually  consist 
of  a  chamber  which  is  attached  to  the  main  at  summits,  and 
which  contains  a  ball  or  float.  An  accumulation  of  air  in  the 
chamber  displaces  the  water,  and  the  consequent  downward 
movement  of  the  float  opens  the  valve,  the  air  escapes,  and  the 
water  re-entering  the  chamber  lifts  the  float,  thereby  closing  the 
valve.  Types  of  automatic  air- valves  are  shown  in  Figs.  84  and  85. 
Mains  which  are  exposed  to  the  weather,  as  is  the  case  with 
pipes  laid  over  streams  or  connected  with  elevated  tanks,  or  which 
are  laid  with  an  insufficient  covering  of  earth  or  other  material,  are 
liable  to  freeze  in  cold  weather  unless  the  circulation  or  flow  of 

*  "Automatic  Water-pipe  Scrapers  at  Melbourne,  Australia,"  Eng. 
News,  Vol.  LIII,  p.  14. 

f  "Experience  with  Mechanical  Scrapers  for  Cleaning  Water-mains 
at  Halifax,  N.  S.,"  Eng.  News,  Vol.  XLIV,  p.  127. 


CARE  OF  APPURTENANCES. 


293 


water  within  the  pipes  is  continuous.  As  measures  of  precaution 
against  this  liability,  pipes  are  surrounded  with  hair-felt,  mineral 
wool,  asbestos,  wool  waste,  or  leather  cuttings;  or  the  pipes  are 
boxed  with  saw-dust,  charcoal,  rosin,  tanbark, 
asphalt,  or  tar-concrete;  or  dependence  is  placed 
upon  air  which  is  confined  by  double  or  single 
boxing,  in  which  case  a  space  of  from  2  to  6 
inches  is  left  between  the  pipe  and  the  sides  of 
the  box. 

The  use  of  any  fibrous  material  will  prove 
ineffectual  if  the  material  becomes  wet,  as  it 
wi:l  then  freeze  and  lose  its  non-conducting  prop- 
erties. The  method  of  boxing  has  been  the 
most  satisfactory  in  many  cases,  provided  there 
is  no  opportunity  for  the  air  within  the  box  to 
circulate.  In  extreme  cases  the  confined  air  has 
been  warmed  by  steam  or  hot-water  pipes  en- 
closed within  the  box  and  supplied  from  a  con- 
venient boiler  or  heater. 

When  service-pipes  are  laid  where  ledge  is 
encountered,  and  the  property-owner  does  not 
desire  to  incur  the  expense  necessary  to  place 
the  pipe  at  the  proper  depth,  the  pipe  may 
be  laid  in  a  somewhat  shallow  trench  and  thoroughly  bedded  in 
asphalt  or  tar-concrete  similar  in  composition  to  that  used  for 
walks. 

Mains  laid  in  or  under  bridges  should  be  provided  with  taps 
or  blow-offs  through  which  the  water  may  be  drawn  off  and  the 
pipe  drained  in  case  it  becomes  necessary  to  shut  off  the  main 
during  cold  weather. 

Notwithstanding  precautions  taken  to  prevent  freezing,  mains, 
hydrants,  and  service  connections,  particularly  the  latter,  occa- 
sionally freeze.  When  the  flow  of  water  within  a  main  is  stopped 
by  the  formation  of  ice,  no  time  should  be  lost,  but  measures 
for  the  restoration  of  the  flow  should  be  at  once  undertaken, 
otherwise  the  formation  of  ice,  which  commences  at  an  exposed 
point,  will  often  continue  for  some  distance  along  the  main. 
If  the  pipe  is  exposed  the  careful  application  of  steam  or  hot 


FIG.  85.— Air- 
valve. 


294 


MAINTENANCE  AND  OPERATION. 


water  will  heat  the  metal  and  thaw  the  ice;  or  the  pipe  may  be 
surrounded  with  unslaked  lime,  which  is  moistened  and  covered 
in  order  that  the  heat  produced  may  be  utilized.  The  application 
of  fire  to  a  frozen  pipe  or  hydrant  is  a  questionable  proceeding, 
as  the  cast-iron  often  cracks  under  this  treatment. 


FIG.  86. — The  Burbank  Thawing  Machine. 

A,  Force-pump;  B,  Coal  Boiler  and  Gasolene  Burner;  C,  Block  tin  Pipe 
on  Reel ;  D ,  Suction  Hose. 


Frozen  hydrants  may  be  thawed  by  steam  generated  in  a 
small  portable  boiler  and  introduced  into  the  hydrant  through  a 
nozzle  by  a  short  hose,  or  hot  water  may  be  pumped  into  the 
hydrant  from  a  pail  heated  over  an  ordinary  plumbers'  furnace. 
After  a  hydrant  is  thawed,  it  should  be  pumped  dry  and  examined 
at  frequent  intervals. 


CARE   OF  APPURTENANCES.  295 

Service-pipes  may  be  thawed  in  like  manner  by  the  use  of  a 
block-tin  pipe  of  &  or  \  inch  internal  diameter,  which  is  inserted 
into  the  pipe  at  the  point  where  the  latter  enters  the  building  sup- 
plied, or  at  the  stop  and  waste  cock.  The  steam  used  is  generated 
or  the  water  heated  in  the  manner  mentioned,  one  man  attending 
to  the  boiler  or  heater  and  a  second  forcing  the  thaw-pipe  into 
the  connection.  The  block- tin  pipe  is  quite  flexible  and  will 
pass  easy  bends  but  not  an  elbow.  If  the  ground  surrounding  the 
service  connection  is  frozen  the  pipe  will  freeze  again  unless  the 
water  is  allowed  to  run. 

To  obviate  the  necessity  of  allowing  the  water  to  flow  con- 
tinuously through  a  service  connection  which  has  been  thawed, 
the  following  method  of  thawing  is  used  at  Holyoke,  Mass.  Steam 
under  50  to  60  pounds  pressure  from  a  portable  boiler  is  used 
through  hose,  to  the  end  of  which  is  attached  a  piece  of  f-inch 
iron  pipe  about  6  feet  long,  provided  with  handles.  With  steam 
on,  the  pipe  is  easily  forced  down  through  the  ground  to  the 
service-pipe,  where  it  is  allowed  to  remain  a  short  time.  This 
operation  is  repeated  at  points  along  the  line  of  the  connection 
until  the  pipe  is  entirely  thawed.  It  has  been  the  experience  at 
Holyoke  that  services  thawed  in  this  manner  do  not  again  freeze 
during  the  season. 

Short  lengths  of  main  may  be  thawed  by  the  use  of  steam  or 
hot  water  used  in  a  manner  similar  to  that  in  the  case  of  services, 
but  larger  boilers  or  heaters,  and  larger  hose  or  thaw-pipes,  are 
required  in  such  cases. 

In  localities  where  the  electric  current  is  available  it  may  be 
advantageously  used  for  thawing  frozen  pipes,  the  heat  produced 
by  the  passage  of  a  current  of  sufficient  strength  through  the 
pipes  being  sufficient  to  melt  the  contained  ice.  This  method 
was  made  practicable  by  Professors  Jackson  and  Wood  of  the 
University  of  Wisconsin  in  1898-99,  and  is  outlined  in  a  circular 
issued  by  that  institution,  as  follows: 

"The  current  which  is  required  for  thawing  service-pipes 
satisfactorily  is  from  200  to  300  amperes.  The  source  of  current 
should  have  a  pressure  of  not  less  than  50  volts.  Where  electric- 
light  lines  carrying  alternating  currents  are  available,  a  transformer 
or  transformers  in  parallel  may  be  used  as  a  source  of  current. 


296 


MAINTENANCE  AND  OPERATION. 


It  is  very  important  that  direct  connection  of  pipes  to  house  lines 
be  avoided  on  account  of  danger  of  fire  in  which  the  house  is  placed 
by  such  connection.  Where  alternating  currents  are  not  available, 
continuous-current  feeder-lines  may  be  used,  but  these  should  be 
entirely  separated  from  the  distributing  network  of  conductors. 

' '  The  accompanying  sketch  will  show  the  way  in  which  the 
appliances  should  be  connected  when  an  alternating  current  is 


To  Primary  Electric  Light  Wires 


Ampere  Meter 


Hydrar 


\u/ 

Water  Bucket 


Pipe  to  be  IhuweU 


FIG.  87.— Thawing  Services  by  the  Electric  Current. 

used  with  transformer.  The  secondary  leads  from  the  transformer 
should  be  quite  large,  such  as  No.  3  B.  &  S.  gauge  or  larger.  In 
making  connection  to  the  pipes,  one  of  the  secondary  leads  should 
be  taken  into  the  house  to  which  the  frozen  service-pipe  leads  and 
contact  made  at  that  point  by  some  form  of  metallic  clamp  or  by 
simply  giving  the  conductor  two  or  three  tight  twists  about  the 
pipe  at  any  point  where  the  pipe  is  exposed  or  at  a  faucet  in  the 
house.  The  other  secondary  lead  should  be  put  in  contact  with 
the  water  system  outside  of  the  house,  and  in  a  similar  manner. 
This  contact  may  be  made  at  a  hydrant,  or  at  an  adjoining  service- 
box,  or  at  pipes  in  a  neighboring  house.  When  there  are  two  houses 
near  together,  each  with  frozen  service-pipes,  the  two  secondary 
leads  may  be  connected  to  the  pipes  within  these  houses  and 
both  frozen  service-pipes  thawed  out  at  once. 

' '  While  the  thawing  process  is  going  on,  the  faucet  should  be 
open  in  the  house  to  which  the  service-pipe  leads.     In  one  of  the 


CARE  OF  APPURTENANCES.  297 

secondary  leads  should  be  inserted  a  water  resistance,  which  con- 
sists (for  convenience)  of  a  bucket  of  water  containing  a  bowlful 
of  salt,  and  two  sheet-iron  or  copper  plates  to  which  the  ends  of 
the  severed  lead  are  attached.  This  serves  to  control  the  current. 
In  the  primary  leads  from  the  electric-light  line  to  the  transformer, 
it  is  highly  desirable  to  have  a  fuse  in  each  lead,  and  an  ampere- 
meter. When  all  connections  are  made,  the  plates  are  placed 
in  the  bucket  and  are  then  moved  towards  each  other  until  the 
ampere-meter  records  a  proper  current.  If  the  primary  pressure  is 
1000  volts  and  the  secondary  pressure  50  volts,  the  current  should 
ordinarily  approach  15  amperes.  If  the  primary  pressure  is 
2000  volts  and  the  secondary  pressure  50  volts,  the  ampere-meter 
reading  should  ordinarily  approach  7.5  amperes. 

' '  Water  ordinarily  begins  to  flow  in  a  time  not  much  less  than 
ten  minutes  or  not  greater  than  one  hour.  If  the  secondary  cur- 
rent is  quite  close  to  300  amperes  the  period  seldom  exceeds  one- 
half  hour.  The  frozen  pipes  are  often  split  by  the  action  ol  the 
frozen  water,  and  these  at  once  begin  to  leak  when  the  ice  is 
thawed  away.  For  this  reason  it  is  desirable  to  have  a  plumber 
where  he  may  be  readily  called  to  care  for  the  leaky  pipe. 

1 '  The  electric  current  when  properly  used  will  not  damage  the 
pipes.  It  is  desirable  to  watch  brass  and  iron  connections  to  lead 
or  iron  service-pipes,  as  they  sometimes  heat  on  account  of  poor 
contact.  If  such  heating  appears  to  be  excessive,  the  current  may 
be  reduced  with  a  resulting  increase  in  the  duration  of  time  for 
thawing. 

1  'After  the  pipe  has  been  thawed  it  is  desirable  to  let  the  water 
run  continuously  for  a  considerable  time,  inasmuch  as  the  ground 
all  around  the  pipe  is  frozen  and  the  pipe  is  liable  to  freeze  up 
again  unless  the  water  circulates." 

This  method  of  thawing  frozen  water-pipes  is  now  used  with 
success  in  a  number  of  works,  and  the  cost  of  thawing  has  been 
found  to  be  about  $4.00  to  $7.00  per  service  thawed.  The  method 
is  applicable  in  the  case  of  frozen  mains,  but  the  current  and 
voltage  and  the  time  required  are  increased.  Several  manufacturers 
of  electrical  apparatus  have  recently  placed  on  the  market  portable 
outfits  designed  for  this  particular  purpose. 


CHAPTER  VI. 
ALTERATIONS  AND   REPAIRS. 

CONTINGENCIES  frequently  arise,  even  in  well-designed  works, 
that  necessitate  alterations  in  existing  structures  before  additions 
can  be  made  thereto.  Such  events  more  commonly  occur  in  con- 
nection with  the  distribution  system.  Provision  must  often  be 


FIG.  88. — Cutting-in  a  Branch. 

made  for  branch  pipes  to  serve  new  streets,  large  consumers,  or 
additional  hydrants.  Connections  with  existing  mains  for  such 
purposes  are  made  in  several  ways.  The  method  commonly  used 
in  the  case  of  small  and  relatively  unimportant  mains  is  to  cut 
out  a  short  section  of  the  pipe  and  insert  in  the  line  a  suitable  special 
casting.  A  short  piece  of  pipe  and  a  sleeve  are  used  to  close  the 
opening  made  in  the  main. 


FIG.  89. — Dunham  Cutting-in  Special. 

A  saving  in  labor  and  material  may  be  effected  by  the  use  of 
a  "cutting-in"  special  in  the  above  instance.  These  specials  are 
so  constructed  that  one  bell  end  can  be  slipped  over  one  of  the 

298 


ALTERATIONS  AND  REPAIRS. 


299 


ends  of  the  severed  pipe  and  the  casting  placed  in  position,  as 
shown  in  Fig.  89. 

Connections  with  large  mains  may  be  made  by  the  use  of  split 
branch  sleeves.  The  two  sections  of  a  sleeve  of  this  kind  are  held 
in  place  by  bolts,  an  opening  of  the  required  size  cut  through  the 
pipe  wall,  and  the  space  between  the  ends  of  the  sleeve  and  the 
pipe  filled  with  lead  and  calked. 

Bolted  sleeves  provided  with  a  boss,  which  is  tapped  to  receive 
a  service  connection,  may  be  used  in  a  like  manner  in  place  of 
the  tapping-band  mentioned  in  Chapter  III. 

The  disadvantage  of  the  above  methods  is  that  the  main 
pipe  to  which  the  connection  is  made  must  be  shut  off  and  drained 


FIG.  90. — Split  Branch-sleeve. 

while  the  work  is  performed.  This  procedure  inconveniences  con- 
sumers, often  to  a  considerable  extent,  and  the  shutting  off  of  a 
large  and  important  main  may  at  times  be  avoided  by  the  use 
of  a  special  tapping-machine.  This  machine  operates  in  a  manner 
somewhat  similar  to  that  of  a  service  tapping-machine,  and  by 
its  use  the  sleeve  is  placed,  the  main  tapped,  and  a  valve  set 
without  discontinuing  the  supply.  Since  these  machines  are 
somewhat  expensive,  they  are  rarely  owned  by  small  works,  but 
are  usually  to  be  found  in  all  large  cities  and  may  be  at  times 
rented. 

The  cutting  of  a  pipe  in  the  trench  by  hand  with  a  chisel 
and  hammer  is  a  slow  and  laborious  process,  and  the  pipe  is  often 
cracked  or  broken  when  cut  in  this  manner.  Several  machines 
have  been  designed  for  this  purpose  and  may  be  purchased  from 
dealers  in  water-works  supplies. 

It  is  practically  impossible  to  separate  two  lengths  of  water- 
pipe  without  injuring  one  of  the  pipes,  when  there  is  a  bead  on 
the  spigot  end  of  one  and  the  joint  has  been  well  calked,  except 


3oo 


MAINTENANCE  AND  OPERATION. 


by  melting  or  cutting  out  a  large  part  of  the  lead  in  the  joint. 
As  a  general  rule,  the  method  of  cutting  by  hand  should  be  used 
only  as  a  last  resort,  as  it  is  very  difficult  and  tedious  work  to 


FIG.  91. — Hall  Pipe-cutter. 

remove  lead  from  a  joint  in  this  manner.  A  wood  fire  may  be 
built  about  the  joint  and  the  lead  slowly  melted,  but  a  gasolene- 
or  kerosene-flame  under  pressure  is  much  more  efficient.  A  No.  3 
Wells  light  was  used  successfully  at  Providence,  R.  I.,  in  1898 
for  melting  out  the  lead  joints  in  a  line  of  24-inch  cast-iron 


FIG.  92. — French  Pipe-cutting  Machine. 

pipe.  A  sheet-iron  hood  was  used  to  concentrate  the  heat  from 
the  burner  upon  the  joint.  Kerosene-oil  was  used  under  a  pres- 
sure of  about  25  pounds  to  the  square  inch,  and  about  two  gal- 


ALTERATIONS     AND  REPAIRS.  301 

Ions  were  consumed  for  each  joint  melted.     The  time  required  to 
melt  out  a  joint  was  about  one  hour. 

An  apparatus  for  melting  the  lead  in  the  joints  of  small  pipe- 
lines may  be  made  with  two  coils  similar  to  those  in  an  ordinary 
plumbers'  furnace,  which  are  attached  to  a  piece  of  iron  pipe. 
This  serves  as  a  handle  and  is  connected  by  rubber  tubing  with 
a  small  tank  partially  filled  with  gasolene.  The  air  in  the  tank 


FIG.  93. — Method  of  Melting  Out  Lead  Joints  of  Water-pipe. 
(Providence  Reports,  1898.) 

is  compressed  to  the  desired  degree  by  a  small  force-pump  and 
the  flame  from  the  burners  directed  against  the  joint. 

The  re-establishment  of  street  grades  at  times  necessitates 
the  re-location  of  the  grade  of  water-pipes,  and  when  supply- 
mains  are  affected  by  such  changes,  the  pipes  must  often  be 
moved  while  under  pressure.  Where  the  ground  under  the  pipe 
is  firm  and  compact,  the  line  may  be  lowered  by  excavating  the 
earth  from  beneath  the  pipes,  leaving  each  length  supported  by 
a  short  section  of  unexcavated  material  or  by  blocking.  The 
line  is  then  carefully  lowered  by  removing  the  material  sup* 
porting  the  pipe  or  by  digging  from  beneath  the  blocking.  The 


302  MAINTENANCE  AND   OPERATION. 

trench  should  be  excavated  of  sufficient  width  to  allow  room 
for  work  and  bracing  should  be  placed  between  the  pipe-line 
and  the  side  of  the  trench  to  prevent  any  lateral  movement  of 
the  main.  Planks  or  timbers  held  in  place  by  iron  screw-braces 
are  used  for  this  purpose.  These  extension  screw-braces  are 
also  very  convenient  in  bracing  the  sides  of  excavations  during 
repairs. 

Where  excavations  for  sewers  or  other  purposes  are  made 
beneath  water-pipes  these  pipes  should  be  supported  in  such 
manner  that  the  line  may  be  held  in  place  if  settlement  of  the 
ground  on  either  side  of  the  excavation  takes  place  while  the 
work  is  in  progress.  Water-pipes  are  usually  supported  from 
timbers  placed  across  the  excavation,  the  main  being  held  by 
ropes  or  chains.  The  supporting  ropes  and  chains  are  kept  tight, 
and  the  water-pipe  maintained  at  grade,  by  inserting  a  pick-, 
handle  or  iron  bar  between  the  supporting  lines  and  twisting 
these  whenever  the  ropes  or  chains  become  slack,  or  when  settle- 
ment of  the  supporting  timbers  tends  to  lower  the  pipe. 

A  more  satisfactory  method  at  times  is  to  support  the  pipe 
from  a  vertical  iron  bar  which  is  provided  with  threads  which 
engage  those  of  a  heavy  plate  upheld  by  cross-timbers.  This 
form  of  apparatus  is  also  of  service  in  raising  or  lowering  mains 
where  the  ground  is  unstable. 

The  excavation  of  frozen  material  is  at  best  expensive,  par- 
ticularly when  picks  and  wedges  only  are  used.  The  building  of 
wood  fires  along  the  line  of  the  trench  results  in  the  thawing 
of  but  a  few  inches  of  the  surface  and  the  adoption  of  this  method 
is  not  usually  advisable.  Better  results  may  be  obtained  by 
the  use  of  unslaked  lime,  which  is  placed  in  a  layer  along  the 
trench,  moistened,  and  covered  with  manure  or  tight  boxes. 
The  thawing  may  be  accomplished  economically  by  the  use  of 
steam  from  a  portable  boiler  if  one  be  available.  At  Provi- 
dence, R.  I.,*  ground  which  was  frozen  to  a  depth  of  from 
12  to  24  inches  was  thawed  by  this  method  at  a  cost  of  about 
1.7  cents  per  square  foot.  Boxes  72  feet  long,  20  inches  wide 
at  the  top,  and  24  inches  wide  at  the  bottom  were  placed  on 

*  Jour.  N.  E.  Water-works  Assoc'n,  Vol.  XIII,  pp.  90,  91. 


ALTERATIONS  AND  REPAIRS. 


3°3 


the  line  of  the  trench,  and  after  all  cracks  and  openings  were  closed 
with  earth  or  bagging,  the  boxes  were  filled  with  steam  under 
about  50  pounds  pressure  from  a  small  portable  boiler.  The 
steam  was  introduced  at  one  end  of  the  box  and  a  small  opening 
was  left  at  the  opposite  end  to  cause  circulation.  The  boxes 
were  built  of  spruce  boards  and  were  made  in  sections  12  feet 
long. 

Water  from  leaks  in  main  pipes  or  service  connections  usually 
appears  upon  the  surface  above  the  point  at  which  the  water 
is  escaping,  unless  the  street  pavement  is  water-tight  or  the 


FIG.  94. — Kellogg  Repair  Sleeves. 

ground  frozen.  In  the  latter  instances  the  water  will  often  appear 
outside  the  limits  of  the  pavement,  or  in  grass  ground  in  which 
the  frost  has  penetrated  to  a  comparatively  slight  depth.  The 
appearance  on  the  surface  will  be  usually  at  a  point  about  oppo- 
site the  leak.  The  water  often,  however,  in  the  above  instances 
follows  trenches  in  which  water  or  sewer  connections  are  laid, 
and  appears  at  the  surface  in  the  immediate  vicinity  of  valve- 
boxes  or  hydrants,  or  finds  its  way  into  the  basements  or  cellars 
of  adjacent  buildings. 

An  exception  to  the  general  rule  is  found  at  times  when  the 


304  MAINTENANCE  AND  OPERATION. 

leak  is  in  close  proximity  to  a  culvert  or  a  defective  sewer.     The 
presence  of  a  leak  may  then  not  be  apparent  at  the  surface. 

Leaks  in  cast-iron  water-pipes  are,  in  general,  due  to  defective 
joints,  cracks,  or  blow-holes  in  the  pipe,  or  pittings  caused  by 
electrolysis.  Leakage  at  a  joint  may  be  usually  remedied  by 
re-calking  the  lead.  Pipes  are  occasionally  laid  with  slight  frac- 
tures at  the  spigot  ends  or  a  pipe  may  be  partially  split  by  the 
freezing  of  the  water  contained  therein.  If  the  crack  is  of  con- 
siderable length,  the  damaged  pipe  is  usually  broken  out  and 


FIG.  95. — Method  of  Repairing  Steel  Main,  Cambridge,  Mass. 

replaced  with  a  new  piece.  If  the  crack  is  short,  a  split  sleeve 
may  be  bolted  about  the  pipe  and  the  space  between  pipe  and 
sleeve  filled  with  lead. 

Cracked  pipes  may  be  repaired  with  the  patent  sleeves  shown 
in  Fig.  94  without  shutting  off  the  water  from  the  main.  The 
sleeve  is  placed  in  position  with  a  gasket  of  asbestos  between 
the  two  sections,  the  joints  at  the  ends  leaded  and  calked.  The 
water  from  the  leak  is  allowed  to  escape  through  a  hole  provided 
for  that  purpose,  in  the  lower  section  of  the  sleeve,  while  the  sleeve 
is  placed  and  secured  in  position,  after  which  the  opening  is  closed 
with  a  screw-plug. 

Leakage  through  blow-holes  in  the  pipe  may  be  stopped  by 
tapping  out  the  hole  and  inserting  a  brass  screw-plug,  or  a  short 
bolted  sleeve  may  be  used. 

Small  leaks  frequently  occur  in  riveted  steel  conduits  and 


ALTERATIONS  AND  REPAIRS  305 

these  are  repaired  whenever  possible  without  discontinuing  the 
supply.  Small  holes  in  the  steel  conduit  of  the  Rochester,  N.  Y., 
water-works  are  closed  with  a  wooden  plug.  A  piece  of  sheet  lead 
somewhat  larger  than  the  hole  is  then  placed  on  the  pipe  and 
covered  with  a  steel  patch,  which  is  held  in  place  by  heavy  iron 
clamps  or  bands  encircling  the  main.  The  outside  edges  of  the 
lead  patch  are  calked.  A  somewhat  similar  method  is  used  in 
Cambridge,  Mass.,  for  repairing  the  steel  mains.  Rubber  packing 
one-quarter  of  an  inch  in  thickness  is  placed  over  the  hole  and 
covered  with  a  steel  patch  five-sixteenths  of  an  inch  thick  rolled 
to  fit  the  outside  of  the  pipe.  The  patch  is  held  in  place  by  shoes 
and  bands  as  shown  in  Fig.  95. 

Some  difficulty  is  at  times  experienced  in  running  lead  joints 
when  water  is  present  in  the  pipe-bell,  as  the  steam  generated  by 
the  heat  from  the  lead  often  loosens  the  pipe-jointer,  thus  permitting 
the  lead  to  escape,  or  blows  out  some  of  the  metal.  When  the 
water  comes  from  the  interior  of  the  pipe-line,  the  flow  may  be 
checked  by  calking  a  piece  of  small  lead  pipe  into  the  joint  before 
yarning;  or  yarn  smeared  with  lard  or  tallow  may  be  used  in 
making  the  joint.  If  but  a  small  quantity  of  water  is  flowing,  oil 
poured  into  the  joint  immediately  before  the  lead  will  be  found 
beneficial. 

Leaks  in  submerged  pipe-lines  are  located  by  shutting  off  the 
line  and  pumping  in  air.  The  character  of  the  leak  is  usually 
ascertained,  and  the  repairs  made,  by  a  diver.  When  split  sleeves 
are  placed  on  submerged  pipes,  the  sleeve  may  be  fitted  to  a  pipe 
similar  to  that  needing  repair  and  the  lead 
joint  poured  but  not  calked.  The  joint  is 
then  cut  in  two,  the  separate  portions  of  the 
joint  and  sleeve  placed,  the  bolts  tightened, 
and  the  lead  calked  by  a  diver. 

The   particular   size    or   pattern  of  split 
sleeve  needed  to  repair  a  damaged  pipe  is  not      pIG.  96.— Clamp, 
always  on  hand  when  wanted,  and  temporary 
repairs  may  be  made  by  winding  rubber  sheeting  or  painted  canvas 
about  the  pipe,  this  being  held  firmly  in  place  by  a  number  of  turns 
of  small  rope  or  by  wire;   or  a  piece  of  rubber  gasket  may  be 
held  tightly  against  the  pipe  by  a  thin  plate  of  wrought  iron 


306  MAINTENANCE  AND  OPERATION. 

hammered  to  fit  the  surface  of  the  main  and  secured  by  suitable 
clamps  or  bands.  An  emergency  clamp  may  be  made  oi  a  piece 
of  strap-iron  of  a  length  somewhat  less  than  the  circumference  of 
the  pipe,  to  the  ends  of  which  angle-irons  are  riveted.  The  angle- 
irons  are  drilled  for  the  reception  of  bolts,  by  which  the  clamp 
is  held  in  place. 

The  common  causes  of  leaks  in  service  connections  are  loose- 
fitting  corporation  cocks  and  imperfect  joints  between  the  pipe 
and  the  stop  and  waste  cocks,  or  between  adjoining  lengths  of  pipe. 
It  is  usually  necessary  in  such  instances  to  shut  the  water  off  at 
either  the  corporation  or  curb  cock  and  tighten  the  defective  joint. 
Defective  cup  joints  in  lead  pipe  should  be  melted  out  and  remade. 
The  threads  of  iron  pipe  on  the  street  side  of  the  house  stop  and 
waste  cock  frequently  rust  away,  when  it  is  necessary  to  cut 
new  threads  and  replace  the  stop-cock  on  the  pipe.  .  When  shut- 
off  cocks  are  not  placed  at  the  curb,  the  water  cannot  be  shut 
off  without  digging  to  the  corporation  cock.  Frequently  the  curb 
cock  is  not  properly  located  and  cannot  be  found  when  wanted 
without  digging.  Several  devices  have  been  made  for  use  under 
these  conditions  to  check  the  flow  of  water  while  making  repairs 
without  recourse  to  excavation  in  the  street.  These  devices  are 
very  similar  in  operation  to  the  ordinary  testing-plug  used  by 
plumbers,  the  pipe  being  closed  by  a  rubber  ring  which  is  com- 
pressed between  two  metallic  discs  and  expanded  against  the 
interior  of  the  pipe.  One  pattern  is  so  constructed  that  the 


FIG.  97. — Thomas-Nusser  Stop-cock  Replacer 

apparatus  may  be  attached  to  the  house  side  of  the  stop-cock,  the 
cock  opened,  the  plug  inserted  a  sufficient  distance  in  the  pipe, 
and  the  stop-cock  removed,  together  with  a  portion  of  the  appa- 
ratus. After  the  new  shut-off  has  been  placed,  or  new  threads 
cut  and  the  old  one  replaced,  the  plug  may  be  removed  by  reversing 
the  method  of  procedure.  No  water  escapes  under  pressure  during 
the  operation. 


ALTERATIONS  AND  REPAIRS.  307 

Service  connections  must  at  times  be  laid  beneath  steam-  or 
electric-railway  tracks,  or  paved  walks  or  driveways,  and  at  such 
times  the  inconvenience  and  expense  incidental  to  the  work 
may  be  reduced  by  the  use  of  machines  designed  to  force  pipe 
through  the  soil,  provided  the  conditions  are  favorable  to  their 
operation.  These  machines  may  also  be  used  to  advantage  for 
renewing  service  connections  under  like  conditions,  or  where 
excavations  in  lawns  are  undesirable.  In  these  instances  the 
ends  of  the  service  connection  and  the  pipe  at  the  curb  cock  are 
made  accessible,  the  old  pipe  withdrawn  and  the  new  placed  by 
attaching  it  to  one  end  of  the  former. 

Leaks  in  earthen  dams  or  reservoir  embankments  should 
receive  prompt  attention  if  the  escaping  water  is  washing  any 
material  out  of  the  structure.  Usually  the  water  must  be  drawn 
down  and  permanent  repairs  made  on  the  water  side  of  the  embank- 
ment. When  located,  the  hole  in  the  bank  is  enlarged  and  the 
opening  carefully  filled  with  well-compacted  puddle.  At  times 
it  may  be  necessary  to  excavate  from  the  top  of  the  bank  to  a 
point  slightly  below  the  leak  and  refill  the  excavation  with  selected 
material. 

Leaks  on  the  water  side  of  masonry  dams,  or  on  the  inside  of 
conduits,  are  often  located  by  throwing  sawdust  into  the  water 
and  noting  the  points  where  the  sawdust  is  drawn  into  the  masonry 
after  the  water  has  been  drawn  down  and  the  surface  exposed. 
Small  leaks  are  occasionally  stopped  in  this  manner.  Large  aper- 
tures should  be  cleaned  and  filled  with  a  grout  of  Portland  cement. 
Cracks  may  be  repaired  by  calking  with  soft  ribbon  lead. 

The  masonry  linings  of  distribution  reservoirs  sometimes 
crack  in  consequence  of  settlement  of  the  underlying  material, 
frost  action,  or  from  other  causes.  Coats  of  plaster  upon  stone 
paving  or  concrete,  if  improperly  applied,  are  liable  to  scale  off 
in  course  of  time,  to  the  detriment  of  the  appearance  and  water- 
tightness  of  the  reservoir. 

Leakage  from  a  reservoir  due  to  the  above  causes  is  remedied 
by  repairing  the  lining  or  by  replacing  it  with  new  material. 
Cracks  or  open  joints  in  an  otherwise  impervious  lining  are  repaired 
by  filling  the  openings  with  asphalt  or  Portland-cement  mortar. 
Old  linings  are  made  more  or  less  water-tight  by  the  application 


308  MAINTENANCE  AND  OPERATION. 

of  asphalt,    Portland-cement    grout,    washes    containing    certain 
chemicals,  or  an  additional  lining  of  concrete. 

Asphalt  was  used  in  repairing  the  Queen  Lane  reservoir  of 
the  Philadelphia  water-works  in  the  following  manner:  "The 
material  used  was  composed  of  4  parts  of  Bermudez  asphalt 
and  i  part  of  the  liquid  or  F  grade  of  Alcatraz  asphalt.  These 
were  melted  together  and  poured  on  the  surface  to  be  treated, 
which  had  been  previously  primed  with  a  thin  coating  consist- 
ing of  3  parts  of  the  F  grade  of  Alcatraz  asphalt  and  7  parts 
of  gasolene.  The  asphalt  was  only  partly  liquid,  and  it  was 
necessary  to  melt  it  before  it  could  be  dissolved  in  the  gaso- 
lene. The  priming  coat  was  allowed  to  dry  thoroughly  before 
the  asphalt  was  applied  over  it,  in  order  that  all  the  gasolene 
might  escape.  The  use  of  this  priming  coat  was  found  to  be 
of  the  utmost  importance.  Asphalt  placed  on  it  adheres  quite 
tenaciously,  while  if  applied  directly  to  the  original  surface  of 
the  cement  concrete,  it  breaks  off  readily."  (J.C.Trautwine,  Jr., 
Trans.  Am.  Soc.  C.  E.,  Vol.  XXXV,  page  93.) 

Some  of  the  basins  connected  with  the  new  filtration  system 
of  the  Philadelphia  water-works  are  lined  with  asphalt  to  insure 
water-tightness  of  the  structures.  As  a  result  of  experiments 
made  to  determine  the  character  of  the  mixture  which  would 
remain  upon  the  slopes  without  creeping,  the  following  mixtures 
were  used.* 

"Floor  and  first  layer  of  slope: 
585  pounds  Seyssel  mastic, 

315       "       grit, 

50       ' '       refined  Trinidad  asphalt, 
50       "  ' '       Bermudez  asphalt. 

"Second  layer  of  slope: 
598  pounds  Seyssel  mastic, 
332       "       grit, 

33       "       refined  Trinidad  asphalt, 
37       "  "       Bermudez  asphalt." 

The  mixture  "containing  the  larger  percentage  of  bitumen 
was  placed  on  the  floor  and  first  coat  of  f  inch  on  the  slopes;  a 

*  Report  of  the  Bureau  of  Filtration,  1903. 


ALTERATIONS  AND  REPAIRS.  309 

second  and  finishing  coat  of  f  inch  containing  slightly  less  bitumen 
was  also  placed  on  the  slopes."  The  asphaltic  linings  were  laid 
|  inch  thick  on  the  concrete  linings  of  the  basins.  As  an  addi- 
tional precaution  against  movement  of  the  layers  on  the  slopes, 
the  surface  of  the  concrete  was  grooved. 

A  small  reservoir  in  Chelsea,  Mass.,  connected  with  the  Metro- 
politan Works  was  repaired  in  1904  by  replacing  portions  of  the 
defective  lining  with  Portland-cement  concrete.*  The  con- 
crete on  the  slopes  was  placed  in  two  layers,  the  lower  being  com- 
posed of  i  part  cement,  2i  parts  sand,  and  6J  parts  crushed  stone 
from  |  inch  to  ii  inches  in  diameter;  the  upper  of  i  part  cement, 
ij  parts  sand,  ij  parts  stone-dust,  and  4  parts  stone.  A  layer 
of  asphalt  about  J  inch  thick  was  placed  between  the  two  con- 
crete layers.  The  asphalt  was  heated  as  hot  as  possible  with- 
out burning  it  and  poured  upon  the  slopes.  Two  coats  of  the 
hot  asphalt  were  applied.  The  upper  layer  of  concrete  was  left 
about'  an  inch  low  and  finished  with  a  coat  of  plaster  composed 
of  i  part  cement,  if  parts  sand,  and  3^  parts  stone-dust,  which 
was  carefully  worked  and  finished  in  a  manner  similar  to  the 
method  used  in  making  granolithic  walks.  This  plaster  coat 
was  applied  while  the  concrete  was  still  moist  in  order  to  secure 
a  perfect  bond  between  the  layers.  The  earth  bank  was  well 
wet  before  any  concrete  was  placed,  and  the  concrete  surfaces 
were  protected  with  moistened  burlap. 

To  secure  the  best  results  with  concrete,  the  sizes  of  the  aggre- 
gates and  the  proportions  of  the  materials  used  should  be  such 
as  to  insure  a  dense  mass,  and  the  materials  should  be  thoroughly 
mixed.  When  dry  mixtures  are  used,  thorough  ramming  is 
necessary  to  fill  the  voids,  and  owing  to  this  fact  concrete  is 
usually  placed  quite  wet  in  order  that  the  mass  may  be  well 
compacted.  Any  plaster  or  finishing  coat  should  be  applied  to 
concrete  before  the  latter  has  set.  . 

Satisfactory  results  have  been  obtained  in  the  waterproofing 
of  walls  of  gate-chambers  and  reservoir  linings  by  the  applica- 
tion of  soap  and  alum  solutions.  The  method  is  known  as  the 


*  "Repairs  to  the  Lining  of  a  Small  Reservoir  on  Powder  Horn  Hill,  Chel- 
sea, Mass."     C.  B.  Saville,  Jour.  N.  E.  Water-works  Assoc'n,  Vol.  XIX. 


310  MAINTENANCE  AND  OPERATION. 

Sylvester  process.  The  soap  solution  is  composed  of  f  pound 
of  soap  dissolved  in  one  gallon  of  water,  and  the  alum 
solution  of  i  pound  of  alum  dissolved  in  four  gallons  of  water. 
The  washes  are  applied  alternately,  the  soap  solution  being 
applied  first  at  a  boiling  temperature.  Twenty-four  hours  are 
allowed  to  elapse  between  the  applications,  and  these  are  con- 
tinued until  the  desired  result  is  obtained. 

In  repairing  a  reservoir  of  the  Pennsylvania  Water  Com- 
pany, this  process  was  used  in  waterproofing  the  old  concrete. 
Two  washes  of  soap  and  two  of  alum  were  applied  at  an  aver- 
age cost  of  about  $2.26  per  thousand  square  feet  of  surface  treated.* 

*  Jour.  N.  E.  Water-works  Assoc'n,  Vol.  XVIII,  p.  180. 


CHAPTER  VII. 
MAINTENANCE  OF  QUALITY. 

A  water- supply  of  satisfactory  quality  and  free  from  pollu- 
tion by  sewage  or  manufacturing  wastes  once  obtained  should 
be  preserved  in  that  condition. 

If  funds  are  available  for  the  purpose,  the  catchment  area 
from  which  a  surface-water  supply  is  derived  should  be  pur- 
chased entire  by  the  municipality.  Otherwise  a  strip  of  land 
bordering  on  the  storage  or  impounding  reservoirs  should  be 
acquired,  and  such  laws  as  may  be  enacted  by  the  legislature, 
or  regulations  framed  by  the  state  board  of  health  regarding 
pollution,  strictly  enforced.  The  location  of  barns  and  stables, 
pig-pens,  privies,  cesspools,  etc.,  on  the  borders  or  in  the  imme- 
diate vicinity  of  storage-reservoirs  and  tributary  streams  should 
be  prohibited.  The  discharge  of  polluting  material  into  or  depo- 
sition near  such  reservoirs  or  streams  should  never  be  permitted. 
Bathing  in  lakes,  ponds,  or  other  sources  of  supply  should  be 
prohibited,  and  boating,  fishing,  and  the  gathering  of  ice  should 
be  allowed  only  under  such  restrictions  as  it  may  be  necessary 
or  desirable  to  impose. 

Surface-water  supplies  are  often  affected  by  growths  of  micro- 
scopic organisms  which  cause  disagreeable  odors  or  tastes. 
Although  the  presence  of  such  organisms  does  not,  as  a  rule, 
impair  the  healthfulness  of  the  water,  the  odors  or  tastes  pro- 
duced by  them  are  at  times  very  objectionable  and  cause  con- 
sumers to  resort  to  the  use  of  water  from  springs  or  wells  for 
drinking  purposes.  In  many  cases  the  water  from  these  latter 
sources  may  be  apparently  of  good  quality  but  in  reality,  owing 
to  sewage  contamination,  its  use  may  be  productive  of  serious 
consequences. 

3" 


312  MAINTENANCE  AND  OPERATION. 

The  cause  of  the  presence  of  these  micro-organisms  in  water- 
supplies  is  not  at  present  definitely  known,  but  the  extent  of  their 
growth  appears  to  depend  in  large  measure  upon  the  amount  and 
character  of  the  organic  matter  present  in  the  water.  This 
organic  matter  may  be  derived  from  accumulations  on  the  water- 
shed, which  are  carried  into  the  streams  and  reservoirs  by  wind 
or  rain,  from  swamps  on  the  catchment  area,  and  from  the 
bottoms  and  shores  of  muddy  ponds  or  storage-reservoirs  which 
have  not  been  properly  prepared  for  the  reception  of  water. 

Water  obtained  from  catchment  areas  which  include  little  or  no 
areas  of  swampy  land,  which  is  free  from  contamination  by  sewage 
or  other  objectionable  material,  and  which  is  retained  in  storage- 
reservoirs  that  have  been  carefully  prepared  by  the  removal  of 
soil  and  organic  matter  from  the  slopes  and  bottoms,  is  rarely 
affected  seriously  by  these  growths. 

A  surface  water-supply  may  be  improved  in  some  cases  by  grub- 
bing and  stripping  the  shores  of  ponds  or  storage-reservoirs  between 
the  high  and  low  water-levels.  Deposits  of  peat  or  mud  on  the 
bottom  of  the  pond  or  reservoir  should  also  be  covered  with  a 
foot  or  more  of  clean  sand  or  gravel.  Improvement  will  also  result 
from  the  filling  or  draining  of  stagnant  pools  and  swamps  on  the 
catchment  area,  since  these  often  serve  as  breeding-places  for 
microscopic  organisms.  In  the  drainage  of  swamps,  the  water 
from  the  uplands  is  intercepted  before  it  enters  the  swamp  and 
conveyed  in  ditches  to  the  reservoir. 

A  large  amount  of  work  of  this  nature  has  been  carried  out 
by  the  Metropolitan  Water  Board,  and  the  methods  used  are 
described  by  Mr.  E.  S.  Larned,  C.E.,  in  a  paper  *  read  before  the 
New  England  Water-works  Association. 

The  methods  used  varied  with  the  character  of  the  swamp;  in 
some  instances  a  single  main  drain  with  cross-drains  was  sufficient, 
and  in  others  drains  entirely  surrounding  the  swamp  were  con- 
structed. The  drains  were  ordinarily  laid  in  sand  or  gravel  below 
the  peat  formation,  thus  intercepting  some  ground-water  as  well 
as  surface-water.  A  cross-section  of  a  drain  as  constructed  is 
shown  in  Fig.  98. 

*  "  The  Drainage  of  Swamps  for  Watershed  Improvement,"  Jour.  N.  E. 
Water-works  Assoc'n,  Vol.  XVI.« 


MAINTENANCE  OF  QUALITY.  313 

"The  drain  has  a  board  bottom,  twelve  inches  wide,  upper  side 
planed,  resting  on  mudsills  2"X4"X2',  spaced  about  3  feet  apart 
and  set  flush  with  the  ground;  on  either  side  are  wood  strips  made 
of  4"  X  4"  stock,  sawed  on  the  diagonal  and  rabbeted  to  set  over 
the  edge  of  the  board  about  three-eighths  of  an  inch,  serving  as  a 
footing  for  the  stone  paving  on  the  sides  of  the  channel,  and  to 


FIG.  98. — Section  of  Drainage  Ditch. 
GOUT.  N.  E.  Water-works  Assoc'n,  Vol.  XVI,  p.  39.) 

hold  the  boards  in  place  when  the  nails  used  may  give  out  through 
the  action  of  rust." 

"  The  side  slopes,  two  horizontal  to  one  vertical,  are  protected 
by  paving  from  6  to  9  inches  thick,  up  to  a  point  above  the  normal 
surface  of  the  water;  at  all  turns  and  connecting  ditches  the 
exposed  slopes  are  protected  by  paving  for  the  full  height; 
paved  gutters  are  made  for  influent  streams  coming  in  from  the 
side." 

The  drainage  ditches  are  designed  to  carry  a  run-off  of  f  of  an 
inch  in  24  hours,  the  maximum  velocity  of  flow  being  fixed  at  2 
feet  per  second. 

The  depth  of  the  drains  or  ditches  varied  from  ij  to  3  feet,  with 
the  average  depth  about  2  feet.  The  cost  of  constructing  about 
9  miles  of  drains  was  approximately  28  cents  per  foot,  exclusive 
of  engineering. 

The  results  obtained  have  been  very  satisfactory,  especially  as 
regards  the  color  of  the  water.  This  has  apparently  been  reduced 
about  30  per  cent.  Fig.  99  shows  the  appearance  of  a  swamp 
before  and  after  the  construction  of  drains. 

The  character  of  the  water  contained  in  a  pond  or  reservoir  of 
a  depth  of  from  about  20  to  200  feet  varies  greatly  during  the 
course  of  a  year,  particularly  if  the  bottom  is  muddy  or  covered 


MAINTENANCE  AND  OPERATION. 

with  deposits  of  organic  matter.  During  the  winter  months  the 
water  at  the  bottom  approaches  the  point  of  maximum  density. 
This  occurs  at  about  39.2  degrees  Fahrenheit  and  the  water  in  the 
lower  layers  is  warmer  than  that  near  the  surface,  which,  although 
colder,  is  lighter.  When  the  ice  breaks  up  in  the  spring  the  surface 
layers  become  warmer  until  the  temperature  throughout  the  mass 
becomes  uniform.  More  or  less  circulation  of  the  water  takes  place 
at  this  time.  Through  the  summer  months  the  upper  layers  of  water 
are  warmer  than  those  near  the  bottom,  and  the  water  lying  below 
the  level  usually  affected  by  wind,  twenty  to  twenty-five  feet, 
remains  stagnant.  In  the  autumn  the  surface-water  becomes 
colder,  the  temperature  of  the  entire  body  becomes  more  uniform, 
and  circulation  again  takes  place.  These  four  periods  are  respect- 
ively termed  periods  of  winter  and  summer  "stagnation"  and 
spring  and  fall  "circulation" -or  "overturning." 

During  the  periods  of  circulation  the  organic  and  mineral 
matter  and  the  products  of  decomposition  which  have  accu- 
mulated in  the  water  of  the  bottom  layers  as  a  result  of  sedi- 
mentation, or  are  dissolved  from  deposits,  are  brought  near 
the  surface,  where  they  afford  a  food-supply  for  microscopic 
organisms. 

If  the  storage-reservoir  is  of  comparatively  limited  extent,  the 
water  of  the  lower  layers  may  be  drawn  off  through  the  waste- 
pipes  previous  to  the  periods  of  circulation  with  a  view  to  the 
limitation  of  the  growth  of  microscopic  life.  During  the  periods 
of  stagnation,  the  supply  may  be  advantageously  taken  from  the 
upper  layers,  if  the  gate-chamber  is  provided  with  intake- valves 
or  ports  for  that  purpose. 

The  microscopic  organisms  which  cause  the  most  trouble 
from  odors  and  tastes  in  surface-water  supplies  are  Asterionella, 
Anabsena,  Clathrocystis,  Ccelosphaerium,  Aphanizomenon,  Dino- 
bryon,  Peridinium,  Synura,  Uroglena,  and  Glenodinium.*  The 
natural  odors  caused  by  these  organisms  and  the  usual  season 
during  which  the  largest  growth  of  the  organisms  occurs  are 
shown  by  the  table  on  page  317. 

*  Whipple,  "Microscopy  of  Drinking-water,"  p.  81. 


Before  Drainage. 


After  Drainage. 
FIG.  99  —Swamp  Drainage  on  the  Metropolitan  Water-works. 


OF  TH 

UN1VER 


MAINTENANCE  OF  QUALITY.  317 

Organism.  Natural  odor.  Season  of  maximum 

_  .  growth. 

Diatomacece. 

Asterionella Aromatic,  geranium,  fishy..    Spring  and  autumn 

Cyanophycece. 

Anabaena Grassy  and  mouldy Summer 

Clathrocystis Grassy 

Ccelosphaerium 

Aphanizomenon 

Protozoa. 

Dinobryon Fishy Spring  and  autumn 

Peridinium Summer 

Synura Cucumber,  bitter  taste.  .  . .  Spring  and  autumn 

Uroglena Fishy,  oily Winter 

Glenodinium Fishy Summer 

The  natural  odors  are  due  to  oils  or  other  substances  con- 
tained in  the  organisms  and  not  to  their  decomposition.  These 
odors  are  intensified  by  the  disintegration  of  the  organisms,  and 
many  of  these  are  broken  up  in  their  passage  through  the  pipes 
of  a  distribution  system  or  by  heat.  On  account  of  this  fact 
the  water  drawn  from  the  service-pipes,  particularly  when  heated, 
will  often  be  objectionable,  while  the  odor  of  the  water  obtained 
directly  from  the  source  of  supply  will  be  only  slightly  noticeable. 
The  odors  due  to  the  decay  of  these  organisms  and  others  not 
mentioned  are  much  more  disagreeable  than  the  natural  odors. 

The  Cyanophyceae  are  often  termed  "  blue-green  algae."  These 
organisms  form  scums  upon  the  surface  of  the  water,  and  the 
odors  produced  when  the  organism  is  decomposed  are  very 
offensive.  At  this  latter  stage  in  the  decay  of  the  organism  the 
odors  produced  are  aptly  termed  "pig-pen"  odors.  "Ana- 
baena, Clathrocystis,  and  Ccelosphaerium  seldom  give  trouble 
unless  the  temperature  of  the  water  is  above  70°  F."  (Whipple, 
Microscopy  of  Drinking-water,  p.  100.) 

When  a  water-supply  is  obtained  from  more  than  one  storage- 
reservoir  it  is  at  times  practicable  to  temporarily  shut  off  the 
supply-pipes  from  the  one  affected  by  organic  growths,  and 
draw  the  water  for  consumption  from  the  remaining  reservoirs. 
A  similar  procedure  may  be  followed  when  the  water  in  a  dis- 
tribution-reservoir is  affected. 

Supplies  derived  from  flowing  streams  without  storage  rarely 
give  trouble  from  odors  or  tastes  caused  by  microscopic  organisms. 


31 S  MAINTENANCE  AND  OPERATION. 

At  the  present  time  little  is  known  with  regard  to  methods 
for  the  removal  from  water-supplies  of  the  odors  or  tastes  pro- 
duced by  micro-organisms.  The  experiments  of  the  Massachu- 
setts State  Board  of  Health  indicate  that  in  some  instances 
single  or  double  nitration  through  sand  may  remove  the  odors 
and  the  organisms  which  produce  them.* 

A  method  originating  with  Dr.  Geo.  T.  Moore  appears  to 
be  of  value  if  carefully  used  when  the  reservoir  or  other  source 
of  supply  is  not  covered  with  ice.f 

This  method  is  known  as  the  "copper  sulphate  treatment." 
The  copper  sulphate  is  added  to  the  water  of  the  reservoir  affected 
in  the  proportion  of  one  part  of  chemical  to  from  one  to  ten  million 
parts  of  water;  the  quantity  of  chemical  used  being  dependent 
upon  the  amount  and  character  of  the  growth  which  it  is  desir- 
able to  destroy,  and  the  temperature  of  the  water.  The  copper 
sulphate  is  placed  in  a  coarse  bag,  which  is  drawn  through  the 
water  from  a  boat  rowed  back  and  forth  on  the  reservoir.  A 
knowledge  of  the  specific  organism  which  is  the  cause  of  the 
objectionable  odor  is  necessary  in  order  that  this  treatment 
may  be  intelligently  applied.  This  information  may  be  obtained 
by  a  microscopical  analysis  of  the  water  affected.  The  best 
results  from  the  use  of  this  chemical  are  apparently  obtained 
during  the  early  stages  of  the  growth  of  the  organisms,  since,  if 
the  growth  is  well  established,  a  second  application  of  the  copper 
sulphate  may  be  necessary.  Furthermore,  if  an  excessive  amount 
of  the  chemical  is  used,  there  is  danger  that  fish,  particularly  the 
smaller  sizes,  will  be  killed,  and  the  healthfulness  of  the  water 
may  be  impaired.  This  method  was  used  successfully,  particu- 
larly for  the  removal  of  Anabsena,  in  a  number  of  instances  during 
the  summer  of  1904. 

Trouble  from  odors  caused  by  microscopic  organisms  is  not 
usually  experienced  when  the  supply  of  water  is  obtained  from 
the  ground  and  stored  in  reservoirs  or  tanks  which  are  covered 
so  as  to  exclude  the  sunlight.  Since  ground -waters  usually 

*  "  Removal  of  Color,  Organisms,  and  Odor  from  Water."  H.  W.  Clark, 
Jour.  N.  E.  Water-works  Assoc'n,  Vol.  XVII. 

t  Bulletins  Nos.  64  and  76,  Bureau  of  Plant  Industry,  U.  S.  Depart- 
ment of  Agriculture. 


MAINTENANCE  OF  QUALITY.  319 

contain  more  or  less  mineral  matter  in  solution  which  forms 
food  for  plant-life,  water  of  this  character  is  very  liable  to 
deteriorate  if  exposed  to  the  light.  Filtered  water  is  also  sub- 
ject to  a  like  deterioration  under  similar  circumstances. 

Ground- waters  are  not,  however,  entirely  free  from  organic 
growths,  as  some  organisms  do  not  require  sunlight  for  their 
development.  Of  these  forms,  Crenothrix  often  causes  trouble 
in  water-supplies  which  are  derived  from  wells  driven  in  swampy 
land,  or  which  are  imperfectly  filtered.  This  organism  causes 
a  precipitation  of  oxide  of  iron,  which  makes  the  water  turbid 
and  objectionable  for  laundry  purposes.  Conditions  favorable 
to  the  growth  of  Crenothrix  are  often  produced  by  excessive 
rates  of  pumping  from  wells  or  filter-galleries.  Aeration  of  the 
water,  or  treatment  with  chemicals  with  subsequent  filtration, 
has  been  employed  for  the  removal  of  the  iron. 

In  general  the  number  of  organisms  found  in  the  water  con- 
tained in  the  pipes  of  a  distribution  system  is  smaller  than  the 
number  present  in  the  water  of  the  source  of  supply.  Growths  of 
Crenothrix  or  some  of  the  varieties  of  fresh-water  sponge,  however, 
occasionally  occur  in  pipe  lines  or  conduits.  Since  many  organ- 
isms require  light  for  their  development  and  existence,  and 
many  disintegrate  when  subjected  to  pressure  or  to  rapid  motion 
of  the  water,  numbers  die  and  decompose  when  carried  into 
the  pipes  of  a  distribution  system.  These  disintegrated  and 
decomposing  organisms  tend  to  collect  at  low  levels  and  at  dead 
ends,  and  accumulations  of  this  nature  at  the  latter  points,  with 
the  accompanying  decomposition,  result  in  a  diminution  or  entire 
exhaustion  of  the  dissolved  oxygen  in  the  water.  In  conse- 
quence water  drawn  from  or  near  dead  ends  is  more  liable  to 
be  affected  by  disagreeable  odors  or  tastes,  and  such  odors  and 
tastes  persist  longer  at  these  points  than  at  others  where  circu- 
lation of  the  water  is  possible.  On  this  account  dead  ends 
should  be  avoided  whenever  possible  and  those  of  a  system 
should  be  thoroughly  flushed  at  frequent  intervals.  During 
the  summer  months,  when  the  temperature  of  the  water  is  com- 
paratively high,  dead  ends  should  be  flushed  once  a  week;  at 
other  seasons  longer  intervals  of  time  between  flushings  may 
be  allowed  to  elapse. 


320  MAINTENANCE  AND  OPERATION. 

It  is  good  practice  to  flush  the  entire  system  of  distribution 
once  or  twice  a  year,  the  water  being  wasted  through  blow-offs 
and  hydrants. 

Sediment  or  organic  matter  should  not  be  allowed  to  accu- 
mulate in  distribution  reservoirs  to  any  large  extent.  Floating 
matters  will  be  driven  to  one  side  of  the  reservoir  by  the  wind 
and  may  then  be  removed  from  the  surface  by  skimming.  Reser- 
voirs with  slopes  paved  with  asphalt,  brick,  or  concrete  are  best 
cleaned  by  the  use  of  brooms,  scrapers,  or  squeegees.  During 
the  operation  of  cleaning,  the  valves  on  the  supply-  and  outlet- 
pipes  are  closed,  the  waste-valve  opened,  and  the  water-level 
gradually  lowered  in  order  that  the  material  on  the  slopes  may 
not  become  dry  before  it  is  removed.  The  cleaning  is  performed 
by  men  working  from  a  raft  which  is  held  against  the  slope  by 
ropes,  and  drawn  along  as  the  cleaning  proceeds.  When  the 
bottom  is  reached,  the  material  is  worked  toward  the  outlet 
and  allowed  to  flow  away  through  the  waste-pipe.  A  hose  stream 
will  be  found  useful  at  this  time  to  stir  up  the  sediment  and 
keep  it  in  motion,  or  the  material  may  be  scraped  into  piles  and 
removed  with  buckets  or  tubs.  The  material  should  not  be 
allowed  to  become  dry,  as  it  then  adheres  to  the  surface  with 
which  it  is  in  contact,  and  if  the  cleaning  of  the  entire  reser- 
voir cannot  be  accomplished  in  one  day,  the  waste-valve  should 
be  closed  at  the  cessation  of  work  and  not  opened  until  the  work 
is  resumed. 

Valuable  aid  in  the  maintenance  of  the  quality  of  a  water- 
supply  is  afforded  by  sanitary  examinations  of  the  catchment 
area  and  the  water  derived  therefrom.  A  complete  sanitary 
examination  of  a  water-supply  consists  of  five  parts:  an  exam- 
ination of  the  catchment  area,  reservoir,  and  tributary  streams, 
a  physical  examination  of  the  water,  a  microscopical  examination, 
a  bacteriological  examination,  and  a  chemical  analysis.  The 
first  is  of  primary  importance,  as  upon  it  depends  the  proper 
interpretation  of  the  results  obtained  from  the  subsequent  exam- 
inations and  analyses.  The  latter  are  also  dependent  in  large 
measure  one  upon  another  for  their  interpretation.  After  the 
general  characteristics  of  a  water  have  once  been  determined, 
partial  examinations  and  analyses  only  are  usually  made,  since 


MAINTENANCE  OF  QUALITY.  321 

the  results  obtained  from  certain  portions  do  not  warrant  the 
expense  involved  in  their  determination. 

The  funds  required  for  the  installation  and  maintenance  of  a 
laboratory  equipped  with  modern  appliances  for  the  examination 
of  water  are  not,  as  a  rule,  available,  except  in  the  case  of  large 
or  extensive  works  supplying  districts  or  the  largest  cities.  How- 
ever, several  States  are  now  following  the  lead  taken  by  Massa- 
chusetts in  the  establishment,  under  the  control  of  the  State 
Board  of  Health,  of  laboratories  and  experiment  stations  of 
this  nature,  and  the  publication  of  the  results  obtained  therein. 
The  excellent  example  set  by  Massachusetts  and  a  limited  num- 
ber of  the  other  States  in  this  respect  will  probably  be  followed 
by  other  States  in  the  future. 

The  physical  examination  of  water  consists  of  the  deter- 
mination of  its  temperature,  turbidity,  the  amount  of  sedi- 
ment, color,  and  odor.  The  turbidity  of  a  water  is  due  to  mat- 
ter in  suspension;  the  color  to  coloring-matters  extracted 
from  leaves,  etc.,  and  held  in  solution.  When  an  analysis  of  water 
is  made  a  sample  is  allowed  to  stand  about  twelve  hours  and 
the  amount  and  general  character  of  the  sediment  noted.  The 
turbidity  or  color  of  a  water  is  expressed  in  arbitrary  units, 
and  is  determined  by  comparing  the  sample  with  standard  solu- 
tions. In  the  former  instance  similar  results  are  obtained  by 
noting  the  distance  below  the  surface  of  the  water  a  platinum 
wrire  of  standard  diameter  disappears  from  view.  Highly  colored 
waters  are  often  improved  in  appearance  by  storage,  with  expo- 
sure to  sunlight,  which  results  in  bleaching,  or  the  drainage  of 
swamps  on  the  catchment  area.  Odors  are  caused  by  living 
organisms,  vegetable  matter  in  solution,  or  organic  matter  which 
is  undergoing  decomposition.  The  odors  vary  with  the  specific 
organism  or  matter  to  which  they  are  due,  and  are  usually  inten- 
sified by  heating  the  sample. 

The  microscopical  examination  is  of  value  for  the  determina- 
tion of  the  cause  of  the  turbidity,  color,  and  odor  observed. 
This  examination  is  of  particular  value  in  the  latter  instance, 
since  the  specific  organism  which  is  the  cause  of  the  odor  may 
be  ascertained  when  the  odors  observed  are  due  to  the  presence 
of  microscopic  life. 


322  MAINTENANCE  AND  OPERATION. 

At  the  present  time  the  bacteriological  examination  is  used 
principally  as  a  means  of  gaging  the  efficiency  of  purification 
methods.  The  bacterial  content  of  a  water  before  and  after 
nitration  is  determined,  and  the  reduction  in  numbers,  expressed 
as  a  percentage,  is  a  valuable  aid  in  the  management  of  filtra- 
tion-plants. When  pollution  by  sewage  or  animal  wastes  is 
suspected,  a  water  is  examined  for  the  presence  of  the  Bacillus 
coli.  This  organism  is  present  in  the  intestines  of  man  and 
warm-blooded  animals,  and  when  found  in  a  water-supply  is 
proof  of  more  or  less  serious  contamination. 

The  chemical  analysis  of  a  water  furnishes  evidence  with 
regard  to  the  amount  and  condition  of  the  organic  matter,  and 
the  quantity  of  mineral  matter  contained  in  the  water  in  ques- 
tion. As  nitrogen  is  an  essential  element  of  all  organic  life, 
determinations  of  the  nitrogenous  matter  present  are  expressed 
as  "albuminoid  ammonia,"  "free  ammonia,"  nitrites,  and  ni- 
trates. Albuminoid  ammonia  represents  the  organic  matter 
present  which  has  not  begun  to  decompose.  Free  ammonia 
is  usually  an  indication  of  the  presence  of  organic  matter  which 
is  undergoing  decomposition.  The  final  stage  in  the  decom- 
position, or  oxidation,  of  organic  matter  is  represented  by  the 
nitrates.  The  nitrites  represent  the  products  of  decomposition 
previous  to  the  final  mineralization  of  the  organic  matter. 
Nitrites  should  not  be  present  in  a  good  ground-water,  and  only 
to  a  limited  extent  in  an  unpolluted  surface-water.  Evidence 
as  to  the  amount  of  organic  matter  present  is  also  given  by  the 
determinations  of  the  "oxygen  consumed,"  "total  organic  nitro- 
gen," and  the  "loss  on  ignition."  Other  determinations  are 
the  "  hardness"  or  soap-destroying  power  of  the  water,  the  amount 
of  iron,  the  "chlorine"  content,  and  the  "total  residue  on  evap- 
oration." The  "fixed  solids,"  or  the  remainder  of  the  "total 
residue"  after  ignition,  is  an  indication  of  the  amount  of  mineral 
matter  present  in  the  water. 

The  chlorine  content  of  a  water  is  of  special  significance, 
since  salt  once  introduced  into  a  water  always  remains  therein. 
A  chlorine  content  in  excess  of  the  normal  for  the  locality  from 
which  the  water  is  derived  affords  evidence  of  either  present 
or  past  pollution  by  the  waste  products  of  animal  life.  If  lines 


MAINTENANCE   OF  QUALITY.  323 

are  drawn  upon  a  map  ^through  the  points  where  the  normal 
chlorine,  that  is  the  chlorine  content  of  an  unpolluted  water, 
is  the  same,  a  series  of  lines  termed  "isochlors"  are  obtained. 
Isochlors  have  been  established  as  a  result  of  systematic  exam- 
inations and  analyses  in  several  States. 

An  excessive  amount  of  chlorine,  free  ammonia,  and  nitrites 
is  usually  an  indication  that  the  supply  is  contaminated  by 
sewage  or  other  objectionable  wastes,  and  that  such  contami- 
nation is  recent.  An  excessive  amount  of  chlorine  and  nitrates, 
in  general,  indicates  that  the  water  has  been  polluted  and  sub- 
sequently purified. 

The  amount  of  foreign  material  present  in  a  water  as  deter- 
mined by  a  chemical  analysis  is  usually  expressed  in  parts  per 
million  or  per  one  hundred  thousand. 


CHAPTER  VTTI. 

WATER    WASTE. 

AT  the  present  time  the  problem  of  reducing  the  waste  of 
water,  which  invariably  occurs  in  all  unmetered  cities  and  towns, 
is  receiving  an  amount  of  attention  from  engineers  and  water- 
works officials  equal  to  that  formerly  given  to  the  problem  of 
securing  additional  supplies,  when  the  demands  for  water  bid 
fair  to  exceed  the  capacity  of  the  source  in  use. 

The  modern  sanitary  requirement  that  water  supplied  for 
domestic  consumption  shall  be  free  from  disease-producing 
organisms,  or  pollution  which  may  give  rise  to  the  presence  of 
these  organisms,  results  in  a  more  rigid  investigation  of  pro- 
posed sources  of  supply,  and  consequently  many  are  now  con- 
sidered unsafe  which  formerly  would  have  been  accepted  with- 
out question.  In  such  instances  resort  must  be  made  to  methods 
of  purification,  and  the  disastrous  experience  of  many  com- 
munities with  polluted  supplies  has  also  made  purification  desira- 
ble, if  not  an  urgent  necessity,  in  many  existing  works. 

The  records  of  consumption  in  various  cities  and  towns 
indicate  that  the  amount  of  water  wasted  often  far  exceeds  the 
quantity  necessary  to  satisfy  the  demands  of  health  or  conveni- 
ence. This  waste  results  largely  from  the  failure  of  the  majority 
of  consumers  to  appreciate  the  value  of  a  supply  of  pure  water. 
The  installation  of  plumbing  fixtures  of  inferior  grade,  which 
remain  tight  but  a  short  time,  the  failure  to  keep  pipes  and  fix- 
tures in  good  repair,  and  carelessness  in  the  use  of  water  impose 
an  unnecessary  burden  on  the  works.  A  continuation  of  these 
conditions  entails  increased  expenditures  for  additional  supplies, 
new  mains,  pumping  machinery,  purification  works,  etc.,  with  a 
corresponding  increase  in  the  annual  expenditures  for  their  main- 


WATER   WASTE.  325 

tenance  and  operation,  and  often  necessitates  the  postponement 
of  measures  designed  for  the  improvement  of  supplies  in  use. 

A  large  proportion  of  the  waste  of  water  is  preventable,  espe- 
cially that  portion  which  has  its  origin  in  the  erroneous 
belief  of  many  consumers  that  water  is  free,  and,  therefore,  to 
be  used  without  regard  to  economy.  This  misuse  of  the  supply 
is  due  to  the  custom  of  many  consumers  to  allow  water  to  run 
freely:  in  the  winter  to  prevent  the  pipes  from  freezing,  in  the 
summer  that  the  water  may  be  cool  for  drinking,  at  all  times 
under  the  impression  that  the  drainage  system  is  kept  cleaner, 
and  to  the  neglect  of  leaky  pipes  and  fixtures  in  order  that  a 
plumber's  bill  may  be  saved.  The  loss  of  water  through  inferior 
fixtures,  the  leakage  of  which  passes  unnoticed  or  is  disregarded 
by  the  average  consumer,  and  the  excessive  use  on  lawns  in 
suburban  districts,  still  further  increase  the  volume  of  waste 
on  the  premises  of  the  water-taker. 

In  this  respect  the  municipality  is  often  equally  at  fault  in 
permitting  the  excessive  use  of  water  in  public  buildings,  espe- 
cially schools,  in  drinking  and  ornamental  fountains,  for  street- 
sprinkling  and  sewer-flushing. 

Still  further  losses  are  due  to  leakage  from  reservoirs,  from 
the  numerous  joints  of  the  pipes  composing  the  supply,  distri- 
bution, and  service  systems,  and  from  small  breaks,  the  leakage 
from  which  does  not  appear  on  the  surface.  In  general  these 
losses  are  practically  non-preventable. 

The  loss  occasioned  by  the  slippage  of  pumps,  referred  to  in 
a  previous  chapter,  is,  strictly  .speaking,  not  a  loss  of  wcter, 
but  of  power. 

The  amount  of  water  required  for  domestic  purposes,  in 
which  may  be  included  that  used  on  lawns  and  in  private  stables, 
varies  from  five  to  fifty  gallons  per  person  per  day,  and  is  depend- 
ent chiefly  upon  the  character  and  mode  of  life  of  the  individual 
consumers.  The  water  used  for  manufacturing  purposes  is  usu- 
ally, or  should  be,  metered,  and  therefore  need  not  necessarily 
be  considered  in  all  investigations  of  waste.  The  following 
statistics  regarding  the  consumption  of  water  in  various  cities 
and  towns  are  of  interest  and  value  in  the  consideration  of  this 
subiect. 


326 


MAINTENANCE  AND  OPERATION. 


METERED  CONSUMPTION  FOR  THE  YEAR  1902  IN  CITIES  AND  TOWNS  WHERE 
METERS  ARE  LARGELY  USED.* 


City  or  town. 

Estimated 
number  of 
consumers. 

Per  cent 
of  services 
metered. 

Total  daily 
average 
metered 
consumption. 
Gallons. 

Gallons  per  consumer 
per  day. 

Domes- 
tic. 

Manu- 
factur- 
ing. 

Totals. 

Brockton   Mass 

37.8°0 
107,650 
35-400 
7,690 
34,474 
5,147 
H9.330 
51,000 

90.0 
96.0 
86.0 
IOO.O 

86.7 

IOO.O 

94.5 
98.7 

822,670 
2,607,100 
1,202,740 
203,430 
762,380 
I32.540 
4,331,030 
2,413,380 

13.2 

15-5 
23.1 

25-4 
ii.  6 
25-6 
16.1 
19.7 

6-5 

5-2 
4.6 
i  .  i 
10.5 

O.  I 

17.8 

22  .O 

21.  S1 
22.  21 

34-Q1 
26.5 

22  .  I 

25-7 

36.  3' 

42.7 

Fall  River,  Mass  
Newton,  Mass  

Ware,  Mass  

Woonsocket,  R.  I  
Wellesley,  Mass  
Worcester  Mass 

Yonkers  NY.     . 

398>49T 

12,475,270 

16.7 

1  Includes  water  used  for  public  purposes. 


CONSUMPTION  OP  WATER  THROUGH  METERS  IN  BELMONT,  MALDEN,  MILTON, 
AND  WATERTOWN,  MASS.* 


City  or  town. 

Number  of 
consumers. 

Gallons 
per  day. 

Gallons  per  day 
per  consumer. 

1901. 

1902. 

1901. 

1902. 

1901. 

1902. 

Belmont.  . 

3,600 
2I.IOO 
6,850 
9,650 

3.900 
22,550 

7.450 
10,250 

63,760 
414,030 
115,000 
147,200 

66,630 
450,160 

143.500 
152,900 

17.7 
19.6 
16.8 
*5-3 

17.1 
20.  o 

s9-3 

14-8 

Maiden  

Milton  

Watertown  

41,200 

44,150 

739,990 

813,190 

18.0 

18.4 

"  In  the  towns  of  Belmont  and  Milton  every  service-pipe  is 
metered,  in  Watertown  89.5  per  cent,  and  in  Maiden  63.4 
per  cent.  The  above  quantities  include  water  used  for  stables 
supplied  in  connection  with  dwellings  and  that  used  for  lawn- 
sprinkling,  as  well  as  that  used  strictly  for  household  purposes. 
In  all  these  municipalities  the  meters  have  been  in  use  but  a 
comparatively  few  years,  and  it  is  not  probable  that  they  have 
become  worn  so  as  to  cause  a  large  percentage  of  error  in  regis- 
tration." * 

*"  Report  on  the  Measurement,  Consumption,  and  Waste  of  Water 
Supplied  to  the  Metropolitan  Water  District."  Dexter  Brackett,  C.E.,  Jour. 
N.  E.  Water-works  Assoc'n,  Vol.  XVIII. 


WATER  WASTE. 


327 


USE  OF  WATER  IN  TENEMENT-HOUSES  IN  BOSTON  DURING  1902.* 


Ward. 

Number 
of 
houses. 

Number 
of 
families. 

Number 
of 
persons. 

Gallons  per  day.     • 

Monthly 
rental. 

Per 
family. 

Per 
capita. 

Ward    6.  . 

21 
8 
13 
15 
2O 
12 
10 
21 
20 
IO 
IO 

9 

263 

75 
155 
I3I 
iji 
116 
88 
209 
250 
in 
89 
81 

1226 
365 

755 
625 

758 
553 
420 

949 
"35 
545 
437 
398 

H5 
71 
64 

U3 
92 
141 
138 

15° 
20O 
I9O 
194 

218 

24.8 

14-5 
13-2 
23-7 
20.7 
29.6 
29.0 
33-i 
43-9 
38.7 
39-5 
44.4 

$12  to  $16 
12  to     16 
16  to     20 
16  to     20 
12  to     20 

20  tO      25 

25  to    30 
25  to    30 
30  to    40 
25  to    45 
35  to    55 
50  upwards 

Ward    7  

Ward    7 

Ward    8 

Ward    9 

Ward    8  .      . 

Ward    8  . 

Ward  10  

Ward  10  

\VT  ard  ii  

Ward  ii  

Ward  ii  

169 

1739 

8166 

139 

29.63 

DOMESTIC  CONSUMPTION  PER  CAPITA  IN  NEWTON,  FALL  RIVER,  WORCESTER, 
AND  LONDON,  ENG..,  AS  DETERMINED  BY  METER  MEASUREMENT.* 


City  or  town. 

Number  of 
houses. 

Number  of 
families. 

Number  of 
persons. 

Con  sumption. 
Gallons. 

Remarks. 

Per 

family. 

Per 

capita. 

Newton 

49° 

49° 

2450 

132.5 

26.5 

All  houses  supplied  with  mod- 

ern plumbing 

Newton.  .... 

— 

619 

3°°5 

— 

6.6 

These  families  have  but  one 

faucet  each 

Newton  

___ 

278 

I  3QO 

"I  A       C 

6   o 

These  families  have  but  one 

m'§ 

x  oy 

•J*T  '  J 

\j  .  y 

faucet  each 

Fall  River.  .  . 

28 

34 

170 

"7.5 

25-5 

The  most  expensive  houses  in 

the  city 

Fall  River.  .  . 

64 

148 

740 

42.0 

8.4 

Average  class  of  houses,  gen- 

erally    having     bath     and 

water-closet 

Worcester.  .  . 

— 

81 

327 

80.2 

19.9 

Woodland  Street,  best  class 

of  houses 

Worcester.  .  . 

— 

37 

187 

H8.I 

23-4 

Cedar   Street,   best    class   of 

houses 

Worcester.  .  . 

— 

93 

447 

95-o 

19.8 

Elm  Street,  houses  of  moder- 

ate cost 

Worcester.  .  . 

— 

245 

1104 

55-1 

12.2 

Southbridge  Street,  cheaper 

houses 

Worcester.  .  . 

— 

229 

809 

55-o 

15-6 

Austin  Street,  cheaper  houses 

London,  Eng. 

1169 

— 

8183 

— 

25-5 

Houses  renting  from  $250  to 

$600;    each  have  bath  and 

two  water-closets 

London,  Eng. 

727 

— 

5089 

— 

18.6 

Middle  class,  average  rental, 

$200 

*"  Report  on  the  Measurement,  Consumption,  and  Waste  of  Water 
Supplied  to  the  Metropolitan  Water  District."  Dexter  Brackett,  C.E.,  Jour. 
N.  E.  Water-works  Assoc'n,  Vol.  XVIII. 


328 


MAINTENANCE  AND  OPERATION. 


In  localities  where  water  is  paid  for  at  meter  rates  and  a 
minimum  rate  established,  the  records  of  the  consumption  in 
cases  where  a  less  quantity  of  water  is  used  than  the  consumer 
is  entitled  to  under  the  minimum  charge  furnish  data  with 
regard  to  the  actual  requirements  for  domestic  purposes.  In 
1888  an  analysis  of  the  accounts  of  consumers  in  the  city  of  Provi- 
dence who  paid  only  the  minimum  rate — this  minimum  being 
$10.00  per  year,  for  which  amount  the  use  of  91.32  gallons  per 
day  was  permitted — showed  the  following  results:  * 


Peranmun. 

167  families  drew  less  than 1500  cu.  ft. 

337  families  drew  the  previous  amount  but 

less  than 2000  cu.  ft. 

361  families  drew  the  previous  amount  but 

less  than 25°°  cu.  ft. 

445  families  drew  the  previous  amount  but 

less  than 3000  cu.  ft. 

446  families  drew  the  previous  amount  but 

less  than 3500  cu.  ft. 

462  families  drew  the  previous  amount  but 

less  than 4000  cu.  ft. 

435  families  drew  the  previous  amount  but 

less  than 4457  cu.  ft. 


:r  Which,  at  5 

day  per  tap.  persons  per  family, 

=   30.742   =»  6.15  gals,  per  capita 

=-   40 . 989   =  8 .  20  gals,  per  capita 

=*   51.236   =-  10.  25  gals,  per  capita 

=   61.484   =•  1 2 . 30  gals,  per  capita 

=-    71.731    —  14-35  gals,  per  capita 

=»   81.978   —  16.40  gals,  per  capita 

™   91.324   =  18.27  gals,  per  capita 


A  similar  analysis  of  accounts  of  the  year  1901  in  the  city 
of  Maiden,  Mass. — where  the  minimum  rate  is  $12.00,  for  which 
amount  the  use  of  130  gallons  per  day  is  permitted — showed  the 
following  results:  | 


~K 

(-, 

au    . 
CJ    <u 

*°8 

«J  u    • 

Cubic  feet  per  year. 

I! 

wa.H 
§££ 

"a" 

Cubic  feet  per  year. 

IE 

§8 

a£g 
&* 

£ 

c3 

2 

3 

Less  than  500 

28 

1  6.4 

Between  3000  and  4000 

566 

72     O 

Between  500  and  1000  . 

52 

'16.1 

Between  4000  and  5000. 

560 

92  .O 

Between  1000  and  2000 

259 

'33-9 

Between  5000  and  6300. 

621 

II4.O 

52  •  5 

2527 

77-4 

1  Many  of  these  were  metered  for  but  a  portion  of  the  year. 

Mr.  Dexter  Brackett  has  engaged  in  many  investigations  of 
the  consumption  and  waste  of  water  in  Boston,  Mass.,  and  vicinity, 

*J.    H.   Shedd,  "Requisite   Amount   of   Water   for  a   Public    Supply," 
Jour.  N.  E.  Water-works  Assoc'n,  Vol.  XVIII,  p.  8. 
t  Jour.  N   E.  Water-works  Assoc'n,  Vol.  XVIII,  p.  146. 


WATER   WASTE.  329 

and  his  estimate  of  the  quantities  required  for  all  legitimate  pur- 
poses by  a  community  is  as  follows: 

Domestic  use 25.0  gallons  per  capita  per  day 

Manufacturing,  mechanical,  and  trade  use. .    23.5 
Public  use 7.0 

Total .    55.5       "      " 

The  estimate  of  the  quantity  required  for  public  use  is  divided 
as  follows: 

Public  buildings 3.78  gallons  per  capita  per  day 

Drinking  and  ornamental  fountains i .  oo 

Street-sprinkling 2.13 

Flushing  water-pipes  and  sewers  and  extin- 
guishing fires 0.20 


Total 7.11* 

The  statistics  which  have  been  given  refer  to  the  average 
consumption;  the  actual  daily  consumption  is  subject  to  more 
or  less  fluctuation  throughout  the  year,  the  departures  from  the 
average  being  usually  more  marked  in  unmetered  communities. 
The  average  consumption  may  be  exceeded  50  per  cent  or  more 
during  days  in  summer  when  water  is  used  extensively  on  lawns, 
and  in  winter  when  water  is  wasted  to  prevent  freezing. 

In  all  metered  cities  and  towns  the  amount  of  water  registered 
by  the  service-meters  is  less  than  the  measured  amount  delivered 
into  the  mains,  the  discrepancy  amounting  to  from  20  to  50  per 
cent  of  the  quantity  supplied.  This  discrepancy  is  probably 
due  to  errors  in  the  various  measurements  caused  by  the  slip 
of  pumps,  by  the  under-registration  of  meters,  and  to  losses 
through  leakage  from  the  mains  and  services  and,  in  some  instances, 
from  unauthorized  connections.  According  to  various  authori- 
ties the  losses  due  to  leakage  from  the  distribution  system  should 
not  exceed  about  3000  gallons  per  day  per  mile  of  main.  How- 
ever, this  figure  is  often  exceeded,  especially  where  compara- 
tively large  leaks  occur  without  any  surface  indications.  In 
1902  four  such  leaks  were  discovered  in  the  course  of  a  waste 
investigation  at  Stoneham,  Mass.,  which  wasted  about  470,000 
gallons  per  day;  similar  investigations  in  Boston  have  disclosed 


33°  MAINTENANCE  AND   OPERATION. 

leaks  amounting  in  single  instances  to  from  24,000  to  100,000 
gallons  per  day. 

The  following  instances  afford  illustrations  of  the  extent  to 
which  water  may  be  wasted  by  a  municipality.  In  the  spring 
of  1903  it  was  found  that  the  consumption  of  water  in  the  pub- 
lic schools  of  Syracuse,  N.  Y.,  was  at  the  rate  of  about  20  gal- 
lons per  pupil  daily,  the  range  being  from  2  to  497  gallons.*  In 
contrast  to  these  figures  the  consumption  of  water  in  metered 
school  buildings  in  the  Boston  metropolitan  district  was  found 
to  vary  from  2.2  to  7  gallons  per  pupil  per  school  day.  Sewer 
flush-tanks  are  in  many  cases  ot  doubtful  value,  and  in  any  case 
should  not  use  more  than  300  to  500  gallons  per  day,  but  57  such 
tanks  in  Richmond,  Ind.,  were  found  using  223,370  gallons  daily, 
the  discharge  from  one  tank  being  at  the  rate  of  17,280  gallons 
in  that  time.f 

Where  meters  are  not  extensively  used  the  larger  portion  of 
the  waste  of  water  takes  place  on  the  premises  of  the  consumers 
as  a  result  of  negligence  or  wilfulness  on  the  part  of  the  latter. 
1 1  The  greatest  source  of  negligent  waste  from  defective  fixtures 
is  undoubtedly  the  ball-cock  which  controls  the  flow  of  water 
into  tanks  supplying  water-closets  and  other  fixtures.  The  ball- 
cock  seldom  remains  tight  more  than  a  few  months,  and  when 
defective  allows  a  constant  stream  of  water,  often  of  considerable 
size,  to  flow  unseen,  though  not  always  unheard,  to  the  sewer. "J 
The  losses  due  to  a  leaky  ball-cock  may  often  be  limited  only 
by  the  capacity  of  the  service-pipe,  and  the  drippings  from  faucets 
may  amount  to  100  gallons  per  day  and  upwards  in  single  instances. 

Investigations  of  Waste. 

In  all  investigations  of  waste  it  is  essential  that  means  be 
available  for  the  determination  of  the  amount  of  water  supplied 

*  "  Municipal  Use  and  Waste  of  Water."  John  Venner,  Jour.  N.  E.  Water- 
works Assoc'n,  Vol.  XV II,  p.  270. 

t  "  Results  of  an  Investigation  of  the  Amount  of  Free  Water  Supplied  to 
the  City  of  Richmond,  Ind."  H.  A.  Dill,  Proc.  Am.  Water-works  Assoc'n, 
1903. 

J  Brackett,  "Report  on  the  Measurement,  Consumption,  and  Waste  of 
Water  Supplied  to  the  Metropolitan  Water  District,"  Jour.  N.  E.  Water- 
works Assoc'n,  Vol.  XVIII,  p.  134. 


WATER   WASTE. 


331 


and  the  variation  in  the  flow  during  twenty-four  hours.  In  the 
case  of  a  direct-pumping  system  computations  may  be  based 
upon  observations  of  the  indications  of  the  pump-counters,  but 
the  results  obtained  are,  however,  often  considerably  in  error, 
owing  to  the  slip  of  the  pumps.  Where  stand-pipes  or  dis- 
tributing reservoirs  of  a  capacity  equal  to  the  daily  consumption 
are  available,  data  may  be  obtained  by  shutting  off  all  other 
sources  of  supply  and  noting  at  intervals  the  decrease  in  height 
of  the  water  surface  of  the  stand-pipe  or  reservoir,  from  which 
the  total  consumption  and  the  consumption  during  each  hour 
of  the  day  may  be  determined.  In  the  latter  instance,  how- 
ever, the  figures  relating  to  the  total  consumption  may  be  affected 
by  leakage  from  the  reservoir,  but  the  differences  in  the  hourly 
rates  should  not  be  appreciably  affected  thereby.  Where  the 


[5000 
[4000 


13000 
'2000 


m 


878910111212315C 


8    9    10  11  12  * 


FIG.  zoo.— Venturi  Meter  Chart. 

reservoir  is  of  comparatively  large  extent  and  the  drop  of  the 
water-surface  small,  observations  of  the  latter  are  of  little  value. 
The  total  consumption  may  be  ascertained  by  a  Venturi 
meter  provided  with  a  register,  and  the  rates  of  flow  at  intervals 
during  the  twenty-four  hours  by  this  apparatus  with  the  addi- 
tion of  a  chart-recorder,  or  by  a  Venturi  tube  and  manometer. 
The  Venturi  meter  has  been  described  in  Chapter  I;  the  manom- 
eter consists  of  a  U  tube  partly  filled  with  mercury,  one  side 
of  the  apparatus  being  connected  by  a  pipe  with  the  inlet  pres- 
sure-chamber of  the  meter-tube  and  the  other  by  a  second  pipe 
with  the  throat  pressure-chamber.  When  water  flows  through 
the  meter-tube  the  inequality  of  the  pressures  at  the  inlet  and 
the  throat  causes  a  difference  in  the  height  of  the  mercury  columns 
in  the  U  tube,  which  is  measured  by  a  sliding  scale  graduated 
to  indicate  the  rate  of  flow  corresponding  to  these  differences. 


332 


MAINTENANCE  AND  OPERATION. 


The  results  obtained  with  this  instrument  are  limited  by  the  num- 
ber of  observations  made. 

The  Deacon  waste-water  meter  has 
been  used  in  the  course  of  waste  in- 
vestigations in  some  English  cities  and 
in  Boston  for  the  determination  of  the 
rates  of  flow.  This  meter  is  set  on  a 
by-pass,  which  with  the  main  pipe-line 
is  provided  with  valves. by  which  the 
flow  may  be  diverted  through  the  meter 
during  experiments. 

' '  The  cast-iron  body  of  the  meter 
contains  a  hollow,  cone-shaped  chamber 
of  brass.  Suspended  in  this  chamber 
C  is  a  composition  disc  D  of  the  same 
diameter  as  the  upper  end  of  the  cone. 
The  fine  wire  by  which  the  disc  is  sus- 
pended passes  through  a  small  hole  in 
the  top  of  the  chamber  over  the  pulley 
R,  and  is  attached  to  a  counterweight 
W.  When  the  water  in  the  pipe  is 
at  rest  the  disc  is  held  at  the  top  of 
the  cone  by  the  counterweight,  but 
when  water  is  drawn  through  the 
meter  the  disc  is  pressed  downward, 
its  position  depending  upon  the  quan- 
tity of  water  passing  through  the 
meter.  By  means  of  a  pencil  attached 
to  the  wire  the  motion  of  the  disc  is 
recorded  upon  a  drum,  £",  revolved  by 
clockwork  once  in  twenty-four  hours. 
The  meter  does  not,  like  the  ordinary 
house  meter,  record  the  total  quantity 
which  has  passed  between  any  two 
observations,  but  it  records  upon  a 

diagram  the  rate  of  flow  at  each  and  every  instant."* 

*  Dexter  Brackett,  C.E.,  "Consumption  and  Waste  of  Water,"  Trans. 
Am.  Soc.  C.  E.,  Vol.  XXXIV,  p.  198. 


FIG.  101. — Manometer. 


WATER   WASTE. 


333 


FIG.  102. — Deacon  Waste-water  Meter. 
(From  Trans.  Am.  Soc.  C.  E.,  Vol.  XXXIV.) 


334 


MAINTENANCE  AND  OPERATION. 


The  meters  used  in  Boston  were  6  inches  in  size,  the  register- 
ing capacity  being  about  25,000  gallons  per  hour.  This  type 
of  meter  on  account  of  its  size  is  not  well  adapted  for  use  in 
measuring  the  flow  in  large  mains. 

Measurements  of  the  flow  of  water  in  a  pipe  with  a  Venturi 
or  Deacon  meter  require  the  cutting  of  the  main  pipe,  and  when 
in  place  the  meter  cannot  be  conveniently  removed  during  the 
course  of  an  investigation.  These  objections  may  be  overcome 
by  the  use  of  a  Cole-Flad  pitorneter,  an  instrument  which  has 


FIG.  103.— Cole-Flad  Pitometer. 

"been  largely  used  in  recent  investigations  of  waste  in  New  York 
and  other  cities. 

"This  instrument  is  primarily  a  rate-meter,  depending  as  it 
does  upon  the  velocity  of  the  water  within  the  main.  .  .  .  Two 


WATER   WASTE.  335 

brass  tubes  bent  at  their  lower  ends  with  carefully  formed  orifices 
of  t  inch  internal  diameter  are  held  in  a  suitable  cap  which 
screws  upon  a  standard  i-inch  corporation  cock  through  which 
the  tubes  may  be  readily  introduced  into  any  main  and  as  easily 
withdrawn.  Heavy  cloth-insertion  rubber  tubing  connects  the 
orifice  tubes  with  a  long  glass  manometer  or  U  tube,  and  blow- 
off  cocks  are  provided  to  remove  air  from  the  instrument.  The 
U  tube  is  half  filled  with  a  mixture  of  carbon  tetrachloride  and 
gasoline  having  a  specific  gravity  of  1.25,  and  when  in  use  the 
water  from  the  pipe  fills  all  the  space  in  the  U  tube  and  con- 
nections. The  orifices  are  set  to  receive  the  maximum  velocity 
within  the  main,  which  is  usually  near  the  center,  and  is  readily 


FIG.  104. — Pitometer  Record. 

indicated  by  the  deflection  in  the  manometer.  This  deflection, 
by  virtue  of  the  differential  action  of  the  water  and  the  slightly 
heavier  and  insoluble  liquid,  is  just  four  times  that  due  to  the 
actual  difference  of  water-head  on  the  orifices  produced  by  the 
flowing  stream.  The  current  impinges  directly  on  one  orifice, 
but  the  other  is  turned  down-stream  and  gives  something  less 
than  the  static  head  within  the  main,  thus  magnifying  the  differ- 
ence of  pressure  produced.  This  difference  is  then  multiplied  in  the 
U  tube,  the  result  being  that  a  low  velocity  within  the  pipe  produces 
a  readable  deflection.  Without  this  effect  the  Pitot  tube  would 
hardly  indicate  a  velocity  less  than  one  foot  per  second,  while 
the  pitometer  may  be  depended  upon,  if  carefully  used,  to  measure 
velocities  as  low  as  4  inches  per  second.  At  the  ordinary  veloci- 
ties the  U-tube  deflections  may  run  up  to  24  inches  and  need 


336  MAINTENANCE  AND  OPERATION. 

not  be  read  with  any  great  nicety.  The  photo-recorder  consists 
of  a  box  in  which  a  drum-carrying  Velox  paper  revolves  before 
a  fine  vertical  slit,  just  in  front  of  which  is  locked  one  leg  of  the 
U  tube  in  such  a  position  that  the  rays  of  light  from  an  oil-lamp 
will  be  partly  intercepted  on  their  way  through  the  colored  liquid 
in  the  lower  half  of  the  manometer.  As  the  liquid  rises  and 
falls  with  the  velocity  in  the  pipe  it  will  record  a  line  or  band  of 
shade  on  the  Velox  paper  whose  ordinates  vary  according  to  the 
well-known  formula 


in  which  h  is  one-quarter  of  the  U-tube  deflection  in  feet  or 
half  the  recorded  ordinate  on  the  paper.  A  1  2-hour  or  48-hour 
photographic  record  is  18  inches  long  and  10  inches  high.  Auto- 
graphic horizontal  lines  are  formed  by  notches  in  the  drum-slit. 
spaced  so  as  to  correct  for  the  angularity  of  the  light  and  enable 
the  deflection  to  be  readily  taken  from  the  diagram  at  any  points 

"  The  accuracy  of  the  pitometer  has  been  established  by 
many  weir  tests  and  by  calibration  in  open  channels  where  the 
absolute  velocities  indicated  by  the  instrument  were  compared 
with  float  measurements. 

"  The  calibration  constant  c  of  the  orifices  has  thus  been 
experimentally  determined  to  be  .800  in  our  formulas. 

"  We  then  have 

V 

in  which  d  is  the  U-tube  deflection  in  feet.  The  actual  velocity 
of  the  water  is  indicated  in  this  way  wherever  the  orifices  may 
be  placed  within  a  pipe,  and  by  completely  traversing  a  given 
pipe  section  on  one  or  two  diameters  we  may  easily  compute 
the  ratio  of  mean  to  maximum  velocity  at  some  one  rate  of  flow. 
This  ratio  once  determined  for  a  given  pipe  is  the  same  at  all 
velocities.  One  may  then  set  the  orifices  permanently  to  give 
the  maximum  or  center  velocity  within  the  pipe,  reading  off  the 
mean  velocity  and  the  discharge  from  a  table  constructed  for 
the  particular  size  of  pipe  and  velocity  ratio."  * 

*  Edward  S.  Cole,  C.E.,"  Water  Waste  and  its  Detection."  Read  Oct. 
22.  1902,  before  the  Western  Society  of  Engineers,  Chicago. 


WATER   WASTE.  337 

Mr.  Cole  considers  that  "the  flow  may  be  determined  by 
the  pitometer  method  within  2  or  3  per  cent  of  the  truth  in  fairly 
clean  pipes  when  the  velocity  exceeds  i  or  2  feet  per  second." 

The  first  step  in  an  investigation  of  waste  is  the  determination 
of  the  probable  amount  of  water  wasted  or  lost,  considering  the 
community  as  a  unit.  In  few  instances  is  water  required  for 
legitimate  purposes  between  midnight  and  four  o'clock  in  the 
morning,  and  the  rate  of  consumption,  as  determined  by  the  use 
of  one  of  the  methods  of  measurement  heretofore  mentioned, 
during  the  intervening  hours  is  usually  a  good  indication  of  the 
amount  of  water  hourly  wasted  and  lost  through  leakage.  Having 
ascertained  these  figures  the  next  step  is  the  determination  of 
the  distribution  of  the  waste.  For  this  purpose  the  city  or  town 
is  divided  into  convenient  sections,  and  by  closing  the  valves  in 
the  mains,  section  after  section  is  cut  off,  the  time  when  a  sec- 
tion is  shut  off  and  the  indication  of  the  measuring  device  being 
noted.  In  like  manner  the  waste  may  be  further  localized  by 
closing  valves  in  the  mains  supplying  the  various  streets.  The 
distribution  of  the  waste  on  the  streets  may  be  best  determined 
by  closing  all  the  valves  on  the  mains  leading  to  the  street  in 
question  and  supplying  the  latter  through  one  or  more  lines  of 
hose  laid  from  a  hydrant  on  an  adjoining  street  to  a  hydrant  on 
the  main  which  is  shut  off.  The  amount  of  water  supplied  may 
be  measured  by  a  service-meter  placed  in  the  hose  line.  The 
losses  from  the  service  connections  beyond  the  curb,  and  the 
leakage  from  the  street  mains  and  services  to  the  curb  cocks, 
may  be  differentiated  by  closing  the  latter  and  noting  both  time 
of  closing  each  and  the  reading  of  the  meter. 

The  loss  due  to  leakage  from  the  latter  portion  of  the  sys- 
tem cannot,  however,  be  determined  with  accuracy  if  the  valves 
in  the  mains  are  not  tight.  Leakage  through  a  valve  will  be 
manifested  by  a  hissing  sound,  which  is  audible  to  a  person  hold- 
ing an  ear  to  the  shut-off  rod,  when  the  latter  is  in  contact  with 
the  valve-stem.  This  hissing  sound  will  be  magnified  by  the 
use  of  a  waterphone,  an  instrument  somewhat  resembling  an 
ordinary  telephone-receiver. 

The  losses  in  some  streets  may  be  so  small  that  it  will  not 
be  necessary  to  carry  the  work  through  to  the  extent  indicated 


338 


MAINTENANCE  AND   OPERATION, 


the  records  obtained  by  the  first  three  methods  outlined  indi- 
cating which  streets  may  or  may  not  be  examined  in  detail. 

The  actual  work  involved  in  an  investigation  of  waste  is  usu- 
ally not  as  simple  as  the  foregoing  brief  outline  may,  perhaps, 
indicate,  particularly  that  in  connection  with  the  determination 
of  the  sub-divisions  of  the  waste.  Old  and  leaky  valves,  abandoned 
service  connections  which  have  not  been  shut  off  at  the  curb  or 
corporation  cock,  unauthorized  or  surreptitious  connections,  the 


FIG.  105. — Aquaphone. 

absence  of  curb  cocks  on  many  service  connections  in  use,  etc., 
introduce  complications  and  increase  the  cost  of  and  time  re- 
quired for  the  experiments.  The  value  of  a  complete  set  of  plans 
and  records  will  be  appreciated  at  this  time  if  not  before. 


Waste  Prevention. 

The  methods  used  for  the  prevention  of  waste  have  been 
limited  in  practice  to  the  following: 

1.  The  extensive  use  of  service-meters. 

2.  House-to-house  inspection. 

3.  The  .Deacon  system. 

The  first  method  requires  no  explanation,  the  second  merely 
locates  and  attempts  to  check  the  waste  beyond  the  curb  cock 
on  the  premises  of  the  consumers,  and  the  third  indicates  the 
waste  substantially  by  the  methods  heretofore  outlined  and  in 
connection  with  the  second  attempts  to  check  it. 

In  the  house-to-house  inspection  system  of  waste  prevention, 
inspectors  test  the  service  connections  at  night  for  leakage  by 
listening,  with  the  aid  of  a  waterphone  and  gate-wrench,  at  thp 


WATER   WASTE.  339 

curb  cock  for  the  hissing  sound  which  is  an  indication  that  water 
is  passing  through  the  latter.  The  sound  is  intensified  by  closing 
the  cock  slowly,  and  is  made  more  evident  in  doubtful  instances 
by  closing  the  cock  entirely  and  then  partly  reopening  it.  If 
no  leakage  is  manifested,  no  further  examination  of  the  premises 
is  made,  but  if  it  is  evident  that  water  is  being  used  or  wasted 
the  fact  is  reported,  and  an  inspector  examines  the  interior  piping 
and  fixtures  during  the  day.  If  leaks  or  defective  fixtures  are 
found  the  property-owner  is  notified  and  requested  to  place  the 
plumbing  in  good  repair. 

The  inspection  methods  have  been  found  expensive,  a  source 
of  annoyance  to  the  occupants  of  suspected  houses,  a  cause  of 
more  or  less  friction  between  the  property-owner  and  the  water 
department,  and  unless  persisted  in  the  results  obtained  are 
not  of  permanent  value. 

On  the  contrary,  the  use  of  meters  has  proved  satisfactory 
to  both  consumers  and  department  in  all  works  where  these 
appliances  have  been  installed.  The  use  of  meters  results  in 
the  co-operation  of  both  parties  in  the  prevention  of  waste  when 
the  water  is  furnished  at  meter  rates  instead  of  schedule  rates. 
"  It  does  this  immediately,  yet  without  need  of  argument  or 
urging.  The  mere  establishment  of  an  instrument  to  keep  a 
record  of  amounts  drawn,  and  the  presentation  of  quarterly  bills 
based  on  such  amounts,  is  all  that  is  needed.  The  bills  convey 
their  own  lesson,  and  it  is  not  possible  to  convey  such  a  lesson 
without  such  bills."  * 

The  value  of  the  water-meter  as  a  waste  preventive  agent 
is  very  forcibly  illustrated  by  the  diagram  (Fig.  106),  pre- 
pared by  Mr.  Freeman,  for  his  report  on  "New  York's  Water- 
supply." 

Further  illustrations  are  afforded  by  the  following  statistics, 
which,  in  connection  with  those  previously  given,  serve  as  the 
best  arguments  in  favor  of  the  use  of  water-meters  for  the  pre- 
vention of  waste. 


*  Clemens  Herschel,  C.E.,  "An  Attempt  to  Prove  that  Thrift  In  the 
Operation  of  Water- works  is  more  Economical  than  Waste."  Proceedings 
Am.  Water-works  Assoc'n,  1901. 


340 


MAINTENANCE  AND  OPERATION. 


EFFECT   OF  THE  USE   OF   METERS   UPON  THE  CONSUMPTION 

OF  WATER   IN   VARIOUS   CITIES. 

Compiled  by  J.  R.  FREEMAN,  C.E 

Quantity  shown  in  gallons  per  inhabitant  per  day. 
Showing  also  the  effect  of  meters  in  restraining 
the  natural  increase  of  consumption  in  recent  years. 
The  curve  A  B  C  is  not  an  exact  average,  but  is 
drawn  as  summing  up  the  general  tendency  and  as 
a  convenient  guide  to  the  eye  in  studying  the  com- 
parative effect  of  various  percentages  of  meters  in 
the  different  cities.  Obviously  the  first  5  or  10  per 
cent  of  meters,  if  judiciously  applied  to  the  worst 
cases  of  suspected  waste,  effect  a  much  larger  saving 
than  any  further  equal  number  of  meters. 


Percent  of  taps  metered 
FIG.  1 06. — Effect  of  the  Use  of  Meters 


8.    &    g 


WATER   WASTE. 


34* 


Nevertheless  service-meters,  useful  as  they  are,  do  not  reduce 
losses  due  to  leakage  from  the  street  mains  and  services,  and  do 
not  entirely  eliminate  waste  on  the  premises  of  the  consumer. 
The  former  losses  may  be  reduced  by  careful  work  in  the  con- 
struction of  extensions  and  service  connections,  and  by  the  repair 
of  breaks  and  defects  in  the  system.  Losses  due  to  the  under- 
registration  of  service-meters  may  be  reduced  by  more  rigid 
requirements  as  regards  the  quality  of  the  plumbing  fixtures  to 
be  connected  with  the  works. 

POPULATION,  WATER  CONSUMPTION,  AND  RECEIPTS  FOR  WATER  SUM- 
MARIZED AND  AVERAGED  IN  ACCORDANCE  WITH  PERCENTAGE  OF  TAPS 
METERED.* 


Consumption, 
gallons  per  day. 

.Receipts. 

Per- 
centage 
of  taps 
metered. 

No. 
of 
cities. 

Popula- 
tion, t 

Total. 

Average 
per 
con- 

No. 
of 
cities. 

Popula- 
tion.t 

Total. 

Aver- 
age 
per 

sumer. 

con- 

sumer. 

o  to     10 

7i 

12,713,866 

1,947,378,000 

153 

53 

11,802,154 

$26,432,316 

$2.24 

10  to     25 

18 

i,6s7,454 

182,991,000 

no 

12 

1,108,142 

2,491,719 

2.25 

25  to    50 

22 

1,686,635 

175,632  ooo 

104 

17 

1,448,633 

3,255,149 

2.25 

50  to  100 

23 

1,600,333 

109,616,000 

62 

20 

1,455.442 

3,253,606 

2.24 

Totals 

an.l 

averages 

134 

17,658,288 

2,415,617,000 

137 

102 

15,814,371 

$35,432,79° 

$2.24 

*  Geo.  I.  Bailey,  C.E.,  "The  Effect  of  Water-meters  on  Water  Consumption  in  the  Large 
Cities  of  the  United  States,"  Engineering  News,  April  18,  1901. 

t  The  table  is  based  on  the  population  supplied  where  separately  reported :  otherwise 
on  the  total  population  by  the  census  of  1900.  The  cities  included  have  populations  of  more 
than  25,000. 


AVERAGE  DAILY  CONSUMPTION  OF  WATER  PER  PERSON  IN  1900  IN  CITIES 
AND  TOWNS  OF  MASSACHUSETTS,  ARRANGED  IN  GROUPS  .ACCORDING 
TO  THE  PERCENTAGE  OF  SERVICES  WHICH  ARE  PROVIDED  WITH  METERS.* 


' 

Gallons  per 
person. 

Average  of  14  cities  and  towns  in  which 
of  the  services  are  metered 

more  than  75  per  cent 

'  39-8 

Average  of  24  cities  and  towns  in  which  more  than  25  per  cent 
but  less  than  7  5  per  cent  of  the  services  are  metered  

47.1 

Average  of  3  1  cities  and  towns  in  which 
cent  of  the  services  are  metered.  .  .  . 

not  more  than  25  per 

59-7 

*  "Consumption    of    Water    in  Cities  and  Towns  in  Massachusetts,"    Report  of  State 
Board  of    Health,   1900,   p.  608. 


MAINTENANCE  AND  OPERATION. 


A  COMPARISON  OF  THE  PER  CAPITA  CONSUMPTION  OF  WATER  IN  CITIES  AND 
TOWNS    WHERE   METERS   ARE    IN    GENERAL    USE    (A)    WITH    THAT   IN 

THOSE    WHERE    WATER    IS    PAID    FOR    AT   SCHEDULE    RATES    (B).* 

(Compiled  by  Dexter  Brackett,  C.E.,  1903.) 
A. 


City  or  town. 

Number 
of 
consumers. 

Per  cent  of 
services 
metered. 

Consumption 
(gals,  per  day 
per  consumer). 

Milwaukee   Wis      

308  ooo 

8o.O 

8l  .0 

Providence    R   I   

198,400 

84.  5 

c8.o 

IIO   33O 

04  •  $ 

68.0 

Fall  River       '     

IO7  ,6^0 

06  .  o 

41  .0 

Lowell              '     

100,000 

6^.O 

57.0 

Lawrence         '     

65,000 

s^.o 

553  .  o 

Brockton         '     

37.800 

90.0 

36  .  o 

3  5,400 

86.0 

54  •  ° 

Woonsocket   R   I  

34  474 

06  .  o 

20  .  o 

^^are   Mass               

7  600 

IOO  .  O 

44  •  ° 

Wellesley   Mass  

e  147 

IOO  .  O 

40  •  o 

Reading         "    

4  38<; 

IOO  .  O 

33.0 

Totals  

I  ,023.276 

61.7 

B. 


City  or  town. 

Number 
of 
consumers. 

Per  cent  of 
services 
metered. 

Consumption 
(gals,  per  day 
per  consumer). 

Buffalo    N    Y      

360,000 

2  .  0 

324  .  o 

Indianapolis    Ind  

169,100 

6.0 

70  •  O 

New  Haven  Ct 

108  ooo 

2    6 

ICO    o 

New  Bedford,  Mass  
Cambridge 

61,000 
04  I  5O 

18.0 
1  1;  .  o 

104.  o 
8c,  .0 

Haverhill                   

37    2OO 

10  .  o 

Qt:  .  o 

Lynn                             

74  ooo 

2  C,  .  O 

63.0 

Waltham                    

24  5  <co 

6.0 

00  •  O 

Salem,                        

36,2  So 

3  .  0 

70  •  O 

Montague,                 

6,1  50 

2  .  O 

73.O 

Dedham                " 

7    CQO 

2  .  O 

83  .O 

Braintree              " 

e  080 

I    O 

Q  I  .  O 

Totals 

083  880 

178  .  c 

In  the  above  table  ' '  an  attempt  has  been  made  to  elimi- 
nate ...  as  far  as  possible  "  differences  due  to  the  effect  upon 
the  consumption  caused  by  "the  differences  in  climate,  in 
character  of  business,  and  in  location,  as  affecting  the  available 
supply  of  water." 

*  Jour.  N.  E.  Water-works  Assoc'n,  Vol.  XV111,  p.  143. 


CHAPTER  IX. 

ELECTROLYSIS. 

THE  recent  wide-spread  introduction  of  street-railways  using 
electricity  as  a  motive  power  presents  a  new  problem  in  the 
maintenance  of  water-works,  that  of  electrolysis.  In  the  usual 
construction  of  railways  of  this  kind  the  single-trolley  system 
is  used;  the  current  is  conveyed  from  the  positive  side  of  the 
generator  by  the  overhead  wires  to  the  trolley  on  the  car,  thence 
to  the  operating  motor,  and  then  returns  to  the  power-house 
through  the  rails,  return-feeders,  water-pipes,  or  other  under- 
ground metallic  structures,  and  the  earth  to  the  negative  side 
of  the  generator.  This  return- current  is  divided  in  accordance 
with  the  established  law  that  the  amount  of  current  which  is 
carried  by  a  number  of  conductors  is  distributed  inversely  as 
the  resistance  of  the  several  paths. 

In  many  cases  the  resistance  offered  by  the  soil  between  the 
rails  and  the  water-pipes  and  the  piping  system  is  comparatively 
small  and  considerable  current  is  diverted  to  the  water-mains, 
where  serious  damage  occurs  at  the  points  where  the  current 
leaves  the  pipes.  At  the  points  where  electrolysis  occurs,  the 
conditions  are  similar  to  those  which  obtain  in  an  electrolytic 
cell.  The  pipe  corresponds  to  the  positive  plate  of  the  cell,  the 
rail,  or  other  metallic  structure,  to  the  negative  plate,  and  the 
moisture  in  the  soil  holding  in  solution  salts  of  the  alkaline  earths 
which  are  readily  decomposed  by  a  current  of  electricity  forms 
the  electrolyte.  A  difference  of  potential  of  about  one  and  one- 
half  volts  is  required  for  the  electrolysis  of  water,  but  the  salts 
ordinarily  found  in  solution  in  the  moisture  present  in  soil  are 
decomposed  by  a  potential  difference  of  a  small  fraction  of  a  volt. 
In  this  latter  instance  the  metal  of  the  pipe  is  attacked  by  the 

343 


344  MAINTENANCE  AND  OPERATION. 

acid  radicals  produced  by  the  decomposition  of  the  soluble  salts. 
To  these  secondary  chemical  reactions  a  large  proportion  of  the 
disintegrating  effect  of  the  current  is  due. 

As  a  result  of  electrolytic  action  the  metal  of  the  pipes  is 
pitted  or  softened.  The  softening  often  occurs  to  such  extent 
that  the  pipe  can  be  cut  with  a  knife  or  nails  driven  into  the  pipe 
wall.  The  pipes  are  reduced  in  thickness  and  strength  until 
ultimately  they  burst  and  more  or  less  damage  and  inconvenience 
results.  The  effect  of  electrolysis  upon  a  cast-iron  water-pipe 
is  shown  in  the  accompanying  illustration  from  the  annual  re- 
port of  the  City  Engineer  of  Providence,  R.  I.,  for  the  year  1903. 


FIG.  107. — Four-inch  Cast-iron  Water-pipe,  showing  Effect  of  Electrolysis. 

The  amount  of  damage  caused  by  stray  electrical  currents  de- 
pends upon  several  conditions.  One  is  the  nature  of  the  salts 
present  in  the  soil.  Professor  Jackson  concludes  as  a  result  of 
experiment  and  investigation  that  the  order  of  activity  of  these 
salts  is  as  follows:  chlorides,  nitrates,  sulphates.*  Another  con- 
dition is  the  character  of  the  material  of  which  the  pipes  are 
composed.  "With  a  given  current  density  and  potential  cast 
iron  is  affected  the  least,  wrought  iron  the  next,  mild  steel  the 
next,  high  carbon  steel  the  next,  and  lead  the  most."  f  The  ex- 
tent of  the  damage  is  also  dependent  upon  the  current  strength 
(amperes)  and  the  time  during  which  the  flow  takes  place.  The 
current  also  depends  upon  the  electrical  pressure  or  potential 
difference,  and  the  resistance  of  the  soil  between  the  pipes  and 


*  ' '  The  Corrosion  of  Iron  Pipes  by  the  Action  of  Electric  Railway 
Currents,"  Jour.  Assoc  of  Eng.  Soc.,  Vol.  XIII. 

t  Report  of  Albert  B.  Herrick,  E.E  ,  to  the  City  Engineer  of  Rochester, 
N.  Y.,  1903. 


ELECTROLYSIS.  345 

the  rails.      The  drier  the*  soil  the  more  resistance  it   offers  to 
the  passage  of  the  current. 

The  amount  of  leakage  from  the  rails  and  other  return  con- 
ductors provided  by  the  street-railway  companies  depends  upon 
the  character  of  the  construction  of  the  road  and  the  amount 
of  traffic.  Owing  to  this  fact  the  amount  of  current  diverted 
to  the  water-pipe  system  may  be  no  larger  in  a  city  where  im- 
proved methods  of  construction  are  used  than  in  a  suburban 
locality  where  the  traffic  is  comparatively  small  but  the  con- 
ductivity of  the  track  return  very  poor. 

Service-pipes,  particularly  those  of  lead,  which  pass  under 
or  near  street-railway  tracks  usually  present  the  first  indica- 
tions of  electrolytic  action.  It  was  observed  in  Peoria,  111.,  that 
about  96  per  cent  of  the  breaks  in  service-pipes  occurring  on 
streets  where  car-tracks  were  laid  took  place  in  instances  where 
the  pipes  passed  under  the  tracks.*  In  this  instance  it  was  also 
observed  that  the  metal  removed  from  the  lead  service-pipes 
was  redeposited  in  other  form  on  the  particles  of  gravel  and  earth 
lying  in  the  path  of  the  current  from  pipe  to  rail. 

The  points  at  which  the  most  serious  injury  to  the  pipes  takes 
place,  or  the  so-called  "  acute"  points,  are  where  the  current  leaves 
the  pipes.  These  are  usually  in  the  vicinity  of  power-stations, 
switches,  and  turn-outs,  or  near  points  where  the  street-rail- 
way tracks  cross  those  of  a  steam  road.  As  the  in  jury  to  main 
pipes  is  in  general  first  evidenced  at  such  points,  it  was  formerly 
deemed  advisable  to  connect  the  water-mains  with  the  rails 
or  negative  side  of  the  generator.  Although  this  method  of  pro- 
cedure proved  beneficial  so  far  as  local  damage  to  the  pipes  at 
the  points  where  the  connections  were  made  was  concerned,  it  was 
found  that  the  method  resulted  in  an  increased  flow  of  current 
through  the  pipe  system. 

Later  investigations  showed  that  the  cast-iron  pipes  of  a  system 
were  not  continuous  conductors,  and  that  the  pitting  and  wast- 
ing away  of  the  pipe  previously  observed  at  the  acute  points 
also  occurred  at  the  joints  in  the  pipe-lines.  Although  the  lead 


*  D.  H.  Maury,  "Electrolysis  of  Underground  Metal  Structures,"  Proc. 
Am.  Water- works  Assoc'n,  1900. 


346 


MAINTENANCE  AND   OPERATION. 


used  in  making  the  joints  between  lengths  of  cast-iron  pipe  is 
a  conductor  of  electricity,  the  protective  coating  applied  to 
the  pipes  serves  as  an  insulating  medium,  and  the  heat  given 
off  by  the  molten  lead  when  a  joint  is  poured  is  not  sufficient  to 
destroy  this  coating.  Experiments  made  by  Mr.  D.  H.  Maury,  C.E., 
and  others  indicated  that  the  resistance  offered  by  the  joints 
of  the  pipe  lines  tested  amounted  to  upwards  of  90  per  cent  of 
the  total  resistance  of  the  line.  In  consequence  of  this  joint 
resistance  a  large  part  of  the  current  carried  by  a  cast-iron  main 
is  shunted  around  the  joints  and  passes  from  one  pipe  to  the 
next  through  the  water  within  the  pipe  and  the  moist  soil  with- 
out. The  pipes  are,  therefore,  pitted  at  the  points  where  the 
current  leaves  the  different  lengths,  as  shown  by  the  accompany- 


FIG.    108. —  Fittings  at  Joint  in   1 2-inch  Cast-iron   Water-main.      Current 
Flowing  from  A  to  B.      (From  Eng.  News,  Vol.  XLIV,  p.  41.) 

ing  illustration  from  the  paper  by  Mr.  Maury,  to  which  refer- 
ence has  previously  been  made.  Wasting  of  the  lead  in  the 
joints  also  occurs,  and  in  consequence  a  joint  so  affected  in  time 
leaks  and  eventually  fails  by  the  blowing  out  of  the  lead. 

Connections  between  water-pipes  and  rails  or  other  return 
conductors  are  now  considered  very  inadvisable  except  as  a  tem- 
porary expedient. 

That  the  damage  occasioned  by  the  passage  of  currents  of 
electricity  through  and  from  the  pipes  of  a  water-works  system 
is  often  of  considerable  moment  is  evidenced  by  the  numerous 


ELECTROLYSIS.  347 

cases  of  injury  to,  or  destruction  of,  pipes  and  appurtenances 
reported  during  the  past  ten  years.  Aside  from  the  question 
of  the  cost  of  replacing  and  repairing  pipes  and  appurtenances 
so  injured,  considerable  damage  may  be  caused  to  adjacent 
property  by  the  sudden  breakage  of  large  mains.  Consumers 
may  also  be  seriously  inconvenienced  if  supply  or  large  distri- 
bution mains  are  affected,  or  the  value  of  a  system  for  fire 
protection  may  be  at  times  greatly  reduced. 

Since  the  cause  of  electrolytic  damage  is  not  under  the  con- 
trol of  the  water  department,  measures  for  the  prevention  or 
diminution  of  such  injury  should  be  undertaken  by,  and  at  the 
expense  of,  the  street-railway  companies.  However,  investiga- 
tions and  tests  should  be  undertaken  by  the  water  department, 
in  localities  where  electric  roads  are  in  use,  in  order  that  data 
with  regard  to  the  existence  or  probability  of  such  damage  may 
be  approximately  ascertained,  and  if  conditions  favorable  to 
electrolysis  obtain,  the  matter  should  be  brought  to  the  attention 
of  the  parties  responsible  therefor. 

As  an  aid  in  the  investigation  of  this  subject  a  map  or  plan 
should  be  prepared  upon  which  the  location  of  water-pipes 
and  appurtenances,  street-railway  tracks,  and  power-stations  is 
shown.  Measurements  are  then  made  of  the  difference  of  poten- 
tial between  pipes  and  rails  at  convenient  points,  and  also  to 
ascertain  the  approximate  current  carried  by  the  pipes.  The 
measurement  of  potential  difference  is  made  with  a  portable 
voltmeter,  with  one  lead  in  contact  with  the  rail  and  the  other 
with  the  water-pipe  or  an  adjacent  hydrant.  An  instrument 
with  the  zero  in  the  center  of  the  scale  is  to  be  preferred,  since 
positive  or  negative  readings  are  recorded  without  the  necessity 
of  changing  connections;  or  two  voltmeters  may  be  coupled 
together,  the  positive  readings  taken  from  one  and  the  nega- 
tive readings  from  the  other.  For  convenience,  voltmeters 
provided  with  two  or  three  scales  should  be  used.  A  millivolt- 
meter  will  be  required  to  measure  very  small  differences  of  poten- 
tial. 

The  voltmeter  measurements  indicate  the  direction  of  the 
current  flow  and  the  electrical  pressure  or  difference  of  potential. 
When  a  positive  reading  is  indicated  by  a  voltmeter  with  the 


348  MAINTENANCE  AND   OPERATION 

positive  binding-post  in  electrical  connection  with  a  pipe  or 
hydrant,  and  the  negative  with  the  rail  or  other  metal  in  the 
ground,  current  will  be  found  to  be  flowing  from  the  pipe. 
On  the  contrary,  if  the  pipe  is  found  to  be  negative  to  the  rail 
the  current  is  flowing  to  the  former. 

The  readings  of  a  voltmeter  will  fluctuate  with  the  move- 
ment of  the  trolley-cars  and  the  observations  made  at  a  given 
point  should  be  extended  to  cover  the  various  conditions  depend- 
ing upon  the  positions  of  the  cars.  The  size  of  the  voltmeter 
readings  at  a  given  point  will  also  vary  with  the  varying  amount 
of  moisture  at  different  periods  of  the  year.  Any  metallic  con- 
nection between  pipes  and  rails  will  tend  to  reduce  the  size  of 
voltmeter  readings. 

The  results  obtained  from  the  observations  with  the  volt- 
meters should  be  noted  upon  the  map  or  plan,  and  notes  with 
regard  to  the  conditions  obtaining  at  the  time  the  readings  were 
taken  should  be  preserved.  The  areas  in  which  the  pipes  are 
negative  to  the  rails,  those  in  which  the  pipes  are  positive,  and 
those  where  they  are  alternately  positive  and  negative  may 
then  be  approximately  determined. 

At  or  near  the  points  where  the  highest  positive  readings  arc: 
obtained  (pipe  to  rail),  excavations  should  be  made  and  the 
pipes  examined  for  evidence  of  electrolytic  action.  Accumu- 
lations of  rust  and  scale  should  be  removed  from  the  exterior 
of  the  pipe,  the  depth  and  size  of  the  pits,  and  the  degree  of  soft- 
ness of  the  metal  noted. 

Measurements  of  the  current  flow  should  also  be  made  where 
the  pipe  is  exposed  in  the  trench.  The  direct  method  of  measure- 
ment is  seldom  applicable,  as  this  would  necessitate  the  cutting 
of  the  pipe,  and  joining  the  ends  with  a  copper  wire,  with  an 
ampere-meter  in  the  circuit.  Usually  the  measurement  of  the 
current  flow  is  made  by  the  "drop-of-potential"  method.  This 
method  is  based  on  Ohm's  law,  that  the  current  varies  directly 
as  the  electromotive  force  and  inversely  as  the  resistance  of  the 

£ 

circuit   or   C=rT,   when   C  =  amperes   of  current,   E  =  volts,  and 

-R  =  ohms  of  resistance.  The  measurement  should  preferably  be 
made  on  a  straight  piece  of  pipe  between  joints,  and  the  con- 


OF  THC 

UNIVER 

OF 


ELECTROLYSIS. 


349 


tacts  of  the  instrument  leads  with  the  pipe  should  be  carefully 
made.  The  drop  of  potential  is  measured  with  a  milli voltmeter. 
The  resistance  of  the  pipe  is  an  unknown  factor,  but  its  approxi- 
mate value  may  be  determined  by  experiments  upon  similar  pipes. 
In  this  instance  currents  of  known  strength  are  caused  to  flow 
through  the  pipe  under  test  and  the  corresponding  drop  of  poten- 
tial in  a  given  distance  measured.  Tables  may  then  be  prepared 
from  which  the  current  flow  in  different  sizes  of  pipe  correspond- 
ing to  the  observed  drop  of  potential  may  be  ascertained;  or 
special  tests  for  the  determination  of  the  resistance  of  cast-iron 
pipe  may  be  dispensed  with  and  the  current  flow  corresponding 
to  the  observed  drop  of  potential  taken  from  the  tables  prepared 
by  Mr.  D.  H.  Maury,  C.E.  The  table  for  use  with  cast-iron  pipe 
is  as  follows: 

CURRENT  FLOW  IN  CAST-IRON  PIPE  WITH  ONE  MILLIVOLT  DROP.* 
(From  tests  showing  average  resistance  per  pound  per  foot  =0.00144  ohm.) 


fi  a> 

ssl 

Distance  in  feet  between  points  of  contact  on  pipe. 

ftj 

•^1 

i 

2 

3 

4 

5 

6 

7 

8 

9 

IO 

"2««  c 

Ilia 

c 

§;£££ 

Current  on  pipe  per  millivolt  drop. 

4 

20 

13-9 

6.9 

4.6 

3-5 

2.8 

2-3 

2  .0 

»  7 

i-5 

1.4 

6 

3° 

20.8 

IO.4 

6.9 

5-2 

4.2 

3-5 

3-o 

2.*6 

2-3 

2  .  I 

8 

39 

27.1 

13-5 

9.0 

6.8 

5-4 

4-5 

3-9 

3-4 

3-° 

2.7 

10 

58 

40.3 

2O.  I 

13-4 

IO.  I 

8.1 

6.7 

5-8 

5-° 

4-5 

4.0 

12 

84 

58.3 

29.1 

19.4 

14.6 

12.0 

9-7 

8-3 

7-3 

6-5 

5-8 

16 

I2O 

83-3 

42  .O 

28.0 

21  .O 

17.0 

14.0 

12.0 

IO.O 

9-3 

8-3 

20 

180 

125.0 

63.0 

42  .0 

31.0 

25.0 

21.0 

18.0 

16.0. 

14.0 

12.5 

24 

220 

153-0 

76.O 

51.0 

38.0 

31.0 

25-5 

22  .0 

19.0 

17.0 

15.0 

30 

310 

216.0 

108.0 

72.0 

54-0 

43-o 

36.0 

31.0 

27.0 

24.0 

22.0 

36 

440 

306.0 

I53-° 

IO2  .0 

76.0 

61  .0 

51.0 

44.0 

38.0 

34-o 

32.0 

42 

560 

389.0 

195.0 

130.0 

97.0 

78.0 

65.0 

56.0 

49-o 

43-° 

39-° 

48 

720 

500.0 

250.0 

167.0 

125.0 

IOO.O 

83.0 

71.0 

62  .0 

56.  c 

50.0 

60 

90O 

624.0 

312  .0 

2O8.O 

156.0 

125.0 

104.0 

89.0 

78.0 

69.0 

62  .0 

*"  Surveys  for  Electrolysis  and  their  Results."  D.  H.  Maury,  Proc.  Am.  Water-works 
Assoc'n,  1903. 

When  the  above  table  is  used,  care  should  be  taken  that 
pipe  bells  or  joints  are  not  included  between  the  points  of  con- 
tact of  the  leads  from  the  instrument. 

The  following  method  for  the  approximate  determination 
of  the  flow  of  current  is  given  in  Herrick's  Electric  Railway  Hand- 
book. Wires  from  a  voltmeter  and  an  ampere-meter  are  inde- 


350  MAINTENANCE  AND   OPERATION. 

pendently  connected  with  points  on  the  water-main.  Readings 
of  the  voltmeter  are  taken  with  the  circuit  through  the  ampere- 
meter open,  and  also  with  this  circuit  closed.  At  the  time  the 
latter  voltmeter  readings  are  taken  the  ampere-meter  is  also  read. 

Then  X:A::Vl:V1-V2  or  X=*V\7  , 

I/I-  1/2 

where  X  =  normal  current  flow  on  pipe, 

A  =  current  diverted  through  the  ampere-meter  circuit, 
FI  =  voltmeter  reading  with  ampere-meter  circuit  open, 
F2=      "  "          "  "  "       closed. 

If  the  connections  of  the  hydrants  to  the  mains  are  electrically 
good,  approximate  results  may  be  obtained  by  this  method  by 
connecting  the  leads  from  the  instruments  with  adjacent  hydrants 
on  the  same  main.  Owing  to  the  uncertainty  with  regard  to 
these  connections,  however,  the  experiments  should  be  made  on 
several  sets  of  hydrants,  or  upon  a  comparatively  short  length  of 
pipe  exposed  in  an  excavation. 

In  all  tests  the  surface  of  the  pipe  should  be  brightened  with 
a  file  and  care  taken  to  secure  good  electrical  connections  between 
the  instrument  leads  and  the  pipe.  The  primary  investigations 
are  preferably  made  under  the  direction  of  an  experienced  engineer, 
but  subsequent  periodical  examinations  may  be  made  by  em- 
ploye's of  the  department  provided  with  suitable  instruments 
for  that  purpose. 

Conditions  favorable  to  electrolytic  action  as  regards  water- 
pipes  are  not  found  when  the  re  turn- current  of  a  street-railway 
system  is  completely  removed  from  the  ground.  The  practicable 
method  by  which  this  removal  may  be  effected  is  the  adoption 
by  the  street-railway  companies  of  the  double- trolley  system.  This 
method  is  not  regarded  with  favor  by  the  railway  corporations, 
since  new  problems  of  construction  and  maintenance  and  con- 
siderable financial  outlay  are  involved  in  a  change  from  existing 
conditions.  Although  the  injury  to  water-pipes  and  appurte- 
nances resulting  from  the  operation  of  electric  railways  by  the 
single- trolley  system  is  now  an  established  fact,  such  legal  actions 
as  have  been  instituted  for  the  purpose  of  compelling  electric- 
railway  corporations  to  change  from  the  single-  to  the  double- 
trolley  system  have  not  as  yet  accomplished  the  end  sought. 


ELECTROLYSIS.  351 

The  flow  of  the  current  from  the  rails  to  the  water-pipes  where 
single- trolley  systems  are  in  use  may  be  reduced  by  the  adoption 
of  better  methods  of  track  construction,  such  as  drainage  of  the 
sub-grade,  the  use  of  heavier  rails,  and  improved  methods  of 
bonding,  and  the  installation  of  overhead  return-circuits  con- 
nected to  the  rails  at  frequent  intervals.  Rail  bonds  often  work 
loose  and  as  a  result  the  efficiency  of  the  track  return  is  greatly 
impaired.  The  electrical  condition  of  the  pipe  system  should, 
therefore,  be  examined  at  intervals  by  the  methods  mentioned. 

It  is  often  assumed  that  serious  damage  will  not  occur  if  the 
readings  obtained  in  voltmeter  tests  do  not  exceed  one  volt,  but 
even  in  these  instances  considerable  injury  may  result  in  the 
course  of  time,  particularly  if  the  soil  surrounding  the  pipes  is 
moist  and  impregnated  with  mineral  salts,  and  the  pipes  are  com- 
posed of  metal  which  contains  many  impurities. 

Care  should  be  taken  in  the  location  of  new  mains  to  place 
the  pipes,  valve-boxes,  and  hydrants  as  far  as  possible  from  the 
rails.  On  the  other  hand,  when  tracks  are  laid  in  streets  which 
contain  water-pipes,  the  rails  should  be  placed  at  a  distance  from 
the  pipes.  The  location  of  tracks  directly  over  and  parallel  to 
water-mains  should  be  avoided  if  possible.  Cast-iron  water-pipes 
may  also  be  advantageously  laid  with  the  bells  toward  the  direction 
in  which  the  current  will  flow,  as  the  wasting  effect  due  to  elec- 
trolytic action  will  then  be  confined  to  the  heavier  and  larger 
bell  ends  instead  of  the  spigot  ends  of  the  pipes. 

Several  methods  have  been  suggested  by  various  writers  for 
the  protection  of  service-pipes  which  pass  beneath  railway  tracks, 
such  as  enclosing  the  service-pipe  in  asphalt,  placing  the  pipe  in  a 
rubber  hose,  or  wrapping  it  with  tape  or  other  insulating  mate- 
rials. When  main  or  service- valve  boxes  are  in  close  proximity 
to  the  rails,  a  portion  of  the  box  may  be  replaced  with  vitrified 
pipe.  Where  the  flow  of  current  is  from  branching  mains  to  a 
large  supply  or  distribution  main,  insulating  joints  have  been 
made  in  the  branch  connection  as  a  means  of  partially  protecting 
the  larger  and  more  important  pipes.  These  joints  consist  of 
two  special  castings  which  are  separated  by  a  heavy  rubber 
gasket. 


CHAPTER  X. 

FIRE  PROTECTION. 

THE  capacity  of  a  system  of  water-works,  particularly  that 
of  the  smaller  distribution  mains,  is  usually  determined  in  large 
measure  by  the  requirements  for  adequate  protection  against  fire. 
When  works  are  first  constructed,  the  amount  of  water  supplied 
for  domestic  and  manufacturing  purposes  is  usually  but  a  com- 
paratively small  proportion  of  the  total  capacity  of  the  system; 
but  as  the  business  of  the  department  increases,  this  amount  like- 
wise increases,  and  the  quantity  of  water  under  suitable  pressure 
for  the  purpose  of  extinguishing  fire  becomes  less.  The  character 
of  the  service  may,  also,  change  as  the  commercial  districts  expand, 
so  that  although  the  provision  for  fire  protection  was  satisfactory 
at  the  outset,  the  increased  demands  for  domestic  and  manufac- 
turing purposes,  together  with  the  additional  requirements  for  fire 
protection  in  the  commercial  and  the  thickly  settled  districts, 
result  in  rates  of  draft  which  reduce  the  available  pressures 
below  "the  points  at  which  satisfactory  service  can  be  given  in 
emergencies. 

A  diminution  of  the  efficiency  of  the  works  in  case  of  fire  should 
be  guarded  against  by  measures  taken  to  restore  or  maintain 
this  efficiency,  provided  the  financial  condition  of  the  works  admits 
of  the  necessary  expenditures  for  that  purpose.  Much  may  be 
done  by  the  installation  of  additional  hydrants,  the  reinforce- 
ment of  the  system  by  the  laying  of  circuit  lines,  and  the  re- 
newal of  some  of  the  older  and  smaller  distribution  mains  with 
pipe  of  larger  diameter.  When  the  pressure  is  inadequate  after 
measures  have  been  taken  to  improve  the  hydrant  service,  de- 
pendence is  usually  placed  upon  steam  fire-engines  when  large 
conflagrations  occur. 

352 


F1AE  PROTECTION.  353 

"•^^ 

The  efficiency  of  an  existing  system  ol  WOIKS  as  a  means  of 
protection  against  fire  may  be  measured  approximately  by  cer- 
tain general  rules  or  standards.  This  efficiency  is  also  at  times 
indicated,  often  to  the  surprise  of  persons  who  have  based  their 
ideas  with  regard  to  the  capacity  of  the  works  upon  static  hy- 
drant pressures,  when  large  demands  are  made  upon  the  works  in 
the  case  of  a  serious  fire. 

The  proper  allowance  for  a  good  fire  stream  is  placed  by 
different  authorities  at  from  175  to  250  gallons  per  minute.  That 
suggested  by  Mr.  John  R.  Freeman,  C.E.,  is  a  stream  of  250  gal- 
lons per  minute,  delivered  through  a  ij-inch  smooth  nozzle,  with 
a  pressure  at  the  base  of  the  nozzle  of  about  45  pounds  per  square 
inch.*  With  this  pressure  a  i-inch  smooth  nozzle  will  deliver 
about  200  gallons  per  minute,  a  J-inch  smooth  nozzle  about 
150  gallons,  and  a  f-inch  smooth  nozzle  about  no  gallons.  A 
stream  of  from  150  to  200  gallons  per  minute  will  usually  prove 
satisfactory  where  fires  occur  in  residential  districts,  the  smaller 
quantity  probably  being  satisfactory  where  buildings  are  so  situ- 
ated that  a  fire  in  one  does  not  greatly  endanger  adjacent  property. 

The  number  of  good  fire  streams  which  should  be  furnished 
simultaneously  from  a  system  is  dependent  upon  the  conditions 
which  obtain  in  a  given  instance  more  than  upon  the  population 
or  valuation.  The  liability  of  considerable  loss  from  fire  is  greater 
and  the  need  of  protection  more  if  in  the  compact  parts  of  the 
city  or  town  the  buildings  are  largely  of  wood.  The  width  of 
streets,  the  character  of  the  industries,  the  nature  of  the  equip- 
ment of  the  fire  department,  whether  or  not  steam  fire-engines 
are  available,  and  the  presence  or  absence  of  streams  from  which 
such  engines  may  derive  their  supply  are  factors  to  be  taken  into 
account  in  the  consideration  of  this  question.  Information  upon 
this  subject  given  by  previous  experience  in  the  handling  of  large 
fires  in  the  municipality  is  also  of  value. 

The  number  of  fire  streams  of  250  gallons  per  minute  each, 
based  upon  the  population  of  the  protected  community,  which 


*  John  R.  Freeman,  "The  Arrangement  of  Hydrants  and  Water-pipes 
for  the  Protection  of  a  City  against  Fire,"  Jour.  N.  E.  Water-works  Assoc'n, 
Vol.  VII. 


354  MAINTENANCE  AND  OPERATION. 

should  be  available  simultaneously  is  considered  by  Mr.  Freeman 
to  be  as  follows:* 

Population.  Number  of  streams. 

1,000  2   to      3 

5,000  4  "     8 

10,000  6    "    12 

20,000  8  "   15 

40,000  12   "  18 

60,000  15     "    22 

100,000  20    "    30 

The  following  recommendations  are  made  by  the  same 
authority:  "So  far  as  a  general  statement  may  apply,  .  .  .  the 
pipes  should  be  large  enough  and  the  hydrants  numerous  enough 
so  that  two-thirds  of  the  above  number  of  streams  could  be  con- 
centrated upon  any  one  square  in  the  compact,  valuable  part 
of  the  city  or  upon  any  one  extremely  large  building  of  special 
hazard.  Better  than  by  data  based  on  population,  the  ques- 
tion of  the  numbei  of  streams  which  it  should  be  possible  to  con- 
centrate at  any  one  point,  as  well  as  the  question  of  the  total 
number  of  fire  streams  to  be  provided  for  the  city,  can  be  best 
solved  Dy  a  tour  around  the  given  city,  studying  out  the  spots 
where  a  large  number  of  streams  would  be  needed  to  check  a 
conflagration  which  may  be  conceived  to  have  so  got  beyond 
control  as  to  hold  some  one  of  the  largest  buildings  in  flames 
from  top  to  bottom  and  from  end  to  end." 

"Ten  streams  or  as  large  a  proportion  thereof  as  the  financial 
consideration  will  permit  may  be  recommended  for  a  compact 
group  of  large,  valuable  buildings  irrespective  of  a  small  popu- 
lation." 

Fig.  109  f  shows  the  number  of  fire  streams,  based  on  popula- 
tion, considered  necessary  by  different  authorities. 


*  See  previous  reference. 

t  Prepared  from  table  and  diagram,  page  15,  of  "The  Financial  Man- 
agement of  Water-works."  E.  Kuichling,  Trans.  Am.  Soc.  C.  E.,  Vol. 
XXXVIII. 


FIRE  PROTECTION. 


355 


It  should  be  borne  in  mind  that  the  quantities  of  water  to  be 
allowed  for  purposes  of  fire  protection  are  in  addition  to  the 
consumption  for  domestic,  public,  and  manufacturing  purposes. 


0  10000        .20000         30000         10000         50000         60000         ,70000         80000          90000      100000 

Population  on  Protected  Area 

FIG.  109. — Number  of  Fire  Streams  Required  in  Cities. 

In  general,  the  amount  of  water  required  for  fire  protection  is 
added  to  the  maximum  hourly  or  daily  rate  of  consumption  for 
other  purposes,  and  provision  is  made  for  a  total  draft  equal  to 
this  amount  for  a  period  of  from  one  to  six  hours. 

The  fire-hose  in  general  use  is  2%  inches  internal  diameter, 
and  the  comparatively  high  velocities  of  flow  when  water  is  dis- 
charged through  a  nozzle  at  rates  of  from  175  to  250  gallons 
per  minute  result  in  a  large  loss  in  pressure  owing  to  the  energy 
consumed  in  overcoming  the  factional  resistance  of  the  hose.  A 
like  loss  of  energy  occurs  when  water  is  drawn  in  large  quantities 
from  long  lines  of  small  pipe. 

In  general,  hydrants  should  be  so  placed  that  hose  lines  of  a 
length  greater  than  500  feet  are  not  required  in  residential  dis- 
tricts, and  of  not  more  than  about  one-half  that  length  in  busi- 
ness or  manufacturing  districts.  The  hydrants  in  a  residential 


356 


MAINTENANCE  AND  OPERATION. 


district,  where  in  the  majority  of  instances  two  good  fire  streams 
are  sufficient,  are  usually  placed  about  500  feet  apart;  but  since 
it  is  advisable  to  place  these  appurtenances  at  street  intersec- 
tions, no  fixed  rule  with  regard  to  the  distance  between  hydrants 
can  be  followed.  When  more  than  two  streams  are  required 
the  average  lengths  of  hose  used  ordinarily  exceed  the  figures 
stated.  If  45  pounds  be  taken  as  the  pressure  at  the  base  of 
the  nozzle,  the  pressures  required  at  the  hydrants  when  the 
streams  are  flowing,  and  the  best  quality  smooth  rubber-lined 
hose  of  2^  inches  internal  diameter  is  used,  are  about  as  fol- 
lows:* 


Length  of  hose. 

Size  of  smooth  nozzle. 

i-inch. 

!-inch. 

i-inch. 

ii-inch. 

Pressure  required  at  hydrant. 

50  feet  

47  Ibs. 

1: 

59 

49  Ibs. 

i;  : 

62     • 

67 

72 

52  Ibs. 

I6 

65 

74 

83 
9i 

56  Ibs. 

8ij 

92 

106    " 

120      " 

100      '   

200      '   

300      '   . 

«*           , 
400          

500       '   . 

Since  the  pressures  at  the  hydrants  usually  range  from  75  to 
100  pounds  in  the  majority  of  instances,  it  follows  that  good 
fire  streams  cannot  under  ordinary  conditions  be  delivered  through 
more  than  300  to  400  feet  of  2j-inch  hose.  The  hydrants  in 
the  commercial  district  should,  therefore,  be  arranged  with  this 
fact  in  view,  and  the  opportunity  to  concentrate  the  number  of 
streams  deemed  necessary  for  efficient  protection  should  be 
afforded. 

In  cases  where  long  lines  of  hose  are  necessary,  or  the  hydrant 
pressures  low,  much  of  the  energy  used  in  forcing  water  through 
the  small  hose  lines  may  be  saved  and  made  available  at  the 
nozzles  by  the  use  of  two  lines  of  hose,  which  are  connected  with 
a  Siamese  coupling  to  one  or  more  lengths  to  which  the  nozzle 

*  John  R.  Freeman,  ''Some  New  Experiments  and  Practical  Tables 
relating  to  Fire  Streams,"  Jour.  N.  E.  Water-works  Assoc'n,  Vol.  IV;  also 
"Experiments  relating  to  Hydraulics  of  Fire  Streams,"  Trans.  Am.  Soc. 
C.  E.,  Vol.  XXI. 


FIRE  PROTECTION. 


357 


is  attached.  This  saving^  is  due  to  the  fact  that  by  the  use  of 
two  lines  from  a  hydrant  the  velocity  of  flow  is  decreased  and 
likewise  the  friction  Josses  in  the  hose. 

Long  lines  of  4- inch  pipe  cannot,  under  ordinary  conditions, 
be  depended  on  to  furnish  a  supply  for  more  than  one  good  hose 
stream,  and  in  some  cases  not  even  one  strong  stream  can  be  made 
available.  With  a  given  loss  of  head  due  to  friction,  the  dis- 
charging capacity  of  a  6-inch  cast-iron  pipe  is  about  three  times, 
and  that  of  an  8-inch  pipe  six  times,  that  of  a  4-inch  pipe  of  equal 
length  and  under  similar  conditions.  The  loss  of  head  in  new, 
clean  cast-iron  pipe,  due  to  friction,  is  about  as  follows  for  pipe 
of  the  diameters  mentioned: 


Discharge, 
gallons  per 

Loss  of  h 

sad  in  feet  per 

1000  feet. 

minute. 

4-inch. 

6-inch. 

8-inch. 

IOO 

200 
300 

400 
SCOO 

7-5 
27.0 
58.0 
97.0 

I  .0 

3-8 
8.0 

13-5 

2O  .   Z 

0.27 

0-93 
I  .96 

3-35 
5  .  10 

6OO 

28.  < 

7  .  OO 

The  advantage  of  using  6-inch  pipe  for  street  mains  instead 
of  4-inch  is  clearly  indicated  by  the  above  table,  and  pipe  of 
larger  diameter  than  4  inches  should  be  used  for  mains  whenever 
possible.  The  minimum  sizes  of  pipe  usually  adopted  for  residen- 
tial districts  are  6-  and  8 -inch,  and  for  commercial  districts,  10- 
and  12-inch. 

The  diagrams  (Figs.  112  and  113)  will  be  found  useful  in  a  study 
of  the  efficiency  of  a  system  as  a  means  of  protection  against  fire. 
The  diagrams  relating  to  the  discharge  of  smooth  nozzles  and 
the  friction  losses  in  hose  are  based  upon  the  experiments  of 
Mr.  Freeman,  to  which  reference  has  been  made.  The  pressures 
at  the  nozzles  and  at  the  hydrants  are  the  pressures  at  these 
points  when  streams  are  flowing.  If  the  elevations  of  the  nozzle 
and  the  hydrant  are  not  the  same,  an  allowance  for  the  difference 
in  height  should  be  made. 


358 


MAINTENANCE  AND  OPERATION. 


The  diagrams  showing  the  friction  losses  in  cast-iron  pipes 
are  based  on  computations  made  by  the  Hazen-Williams  for- 
mula: * 


v  = 


10 

20      30      & 

50      60 

70      80      90     100 

/ 

/ 

' 

/ 

~£_ 

/ 

40 

£ 

£ 

: 

>    2fl 

/ 

y 

X* 

100 

/ 

80 

t 

2 

60 

X 

'V 

> 

/ 

j 

~ 
*/ 

/ 

\/ 

20       -y 

X 

/ 

0  ^- 

/ 

/ 

20      30 

t 

b 

60 

70      80 

/ 

/ 

Pre    ur 

ir.     P 

r  sq 

1  1. 

y 

^, 

r 

/ 

^ 

10*0 

/ 

^ 

-~ 

tie   ^ 

J-- 

/ 

/ 

^ 

^ 

$0 

J^* 

^ 

y 

"• 

&/ 

'"^t^ 

a^- 

/ 

^  •* 

Rft 

^  X 

~'*^^L 

NO'    • 

/ 

/ 

^ 

/ 

^T      ' 

^~** 

/ 

/ 

^X 

^ 

^^" 

y 

0' 

^, 

-^ 

~z  t 

^ 

I 

60 

y 

!  *v  ^ 

1 

/ 

^ 

X  ? 

/ 

S 

S 

V- 

^ 

'     1 

/ 

' 

/ 

A 

1           * 

/ 

I 

~f 

/ 

\ 

> 

/          7 

r            HEIGHT 

OF  FIRE  STREAMS 

^    DISCHARGE  OF  SMOOTH  NOZZLES. 

20           / 

f 

A 

FRE 

2CORDING.TO 
EMAN--S  TABLES. 

y 

/ 

( 

ACCORDING 
EMAN'S  TA 

TO 

BLES. 

"  FRE 

0       10      2        30     40      50      60      70      80      90 
Pressure  at  Nozzle: 'Ibs. 


s 

M 


10   20   30   40   50   60   70   80   80   100 
Pressure  at"Nozzle:'lbs. 


FIG.  no.  —  Height  of  Fire  Streams  and  Discharge  of  Smooth  Nozzles. 

in  which  v  =  velocity  of  flow  in  feet  per  second; 

c  =  coefficient  of  roughness,  which  has  been  taken  as  130 


*  More  complete  diagrams  based  on  this  formula  and  comparisons  with 
other  formulae  and  data  are  given  in  a  paper  "  Hydraulic  Diagrams  and 
Further  Notes  Upon  the  Hazen-Williams  Slide  Rule,"  by  Leonard  Metcalf, 
C.E..  Eng.  Record,  Vol.  47. 


FIRE  PROTECTION. 


359 


for  new,  clean  pipes  and  100  for  old  and  tubercu- 
lated  pipes; 


Pressure  at  Nozzle:  Ibs. 
0       10     20      30      40      50      60      70     80 


(  Pressure  af3£ozzle%  Ibs.., 
10     20      30      40      50      60      70     SO      90    TOO 


10     20      30      40      50     60      70      80      90 
Pressure  at. Nozzle:  Ibs. 


10      20       30      40      50      60      70      80 
Pressure  at  Nozzle: 


90     100 


FIG.  in. — Friction  Losses  in  Ordinary  Best  Quality  Smooth  Rubber-lined 

2. \ -inch  Hose. 


r==  hydraulic  mean  radius 

pipes; 
s  =  slope 


diameter  in  feet 


for  circular 


head 


length* 


3  6o  MAINTENANCE  AND  OPERATION. 

The  following  example  illustrates  the  use  of  the  diagrams. 
Assume  that  a  stream  of  150  gallons  per  minute  is  required  from 
a  |-inch  smooth  nozzle  at  the  end  of  300  feet  of  hose.  Then  the 
pressure  at  the  nozzle  should  be  45  pounds,  and  if  the  nozzle  is 
20  feet  above  the  hydrant,  the  pressure  at  the  hydrant  should 
be  62  +  9,  or  71  pounds.  If  the  hydrant  is  supplied  by  a  6-inch 
pipe  2000  feet  long,  the  pressure  in  the  main  to  which  the  6-inch 
line  is  connected  should  be  about  73  pounds. 

Where  hydrants  are  located  on  mains  supplied  through  several 
pipes  of  different  diameters,  laid  at  different  times,  computa- 
tions of  friction  losses  consume  considerable  time,  and  the  results 
obtained  are  often  very  uncertain.  '  A  better  plan  in  such  cases 
is  to  experiment  on  the  ground  by  attaching  a  pressure-gage  to 
the  main  or  a  hydraixt  and  noting  the  indications  at  varying  rates 
of  draft. 


Loss  of  Head  Due  to  Friction  in  I 

P         p       p     p    p    p 

.r^  %•,»  %s  '   ,  V*^         r<~>       »-*• 


* 

"*           X 

1 

1 

T 

! 

B 

^  <ff 

'^rv 

c 

\ 

v>v 

Xv 

/ 

x 

^ 

X 

X, 

\ 

^ 

\ 

^ 

X 

/ 

NSN 

\ 

x^ 

\ 

"\^ 

\ 

2 

**  ^ 

^\ 

"X 

X 

x 

X. 

^Ssx^ 

\ 

2 

X 

v^ 

»j 

x^^ 

/ 

x 

x 

^^x^ 

^x 

r^ 

/ 

X 

^N 

"x^ 

"X, 

x,^ 

O 

'x.^ 

^x 

\ 

x 

•H                                    • 

^x^ 

x. 

4-|                       A(\f\ 

x^ 

x^ 

^5 

^x 

** 

^x,^ 

^x 

/ 

v- 

\ 

I                                   — 

J      £  500-^ 

^^  

§s 

H 

-x 

T 

in 

-/• 

I 

§  £•»= 

P          P              "X^ 

s 

— 

2    "g 

^x. 

2 

"X^ 

v 

X 

x  s 

\ 

0          £§ 

^x.^ 

/ 

X. 

x 

ss/ 

^X^ 

2        g 

x/ 

s 

\ 

'   \ 

2s 

x 

/ 

\ 

515         £ 

/           ^^v 

X. 

x 

E   » 

"x^^^^ 

x 

x. 

0            2000  
$ 

/ 

x 

X 

/ 

nA- 

Xr^  ~ 

=Xt 

X 

X 

5 

x 

i 

3000 
3500—  / 

7000  

-t- 

/. 

rT 

/ 

^          / 


per  1000  Feet  of  Pipe 


•fiT  m 


' 


ouoi  i      g 

1 


\ 


\ 


Loss  of  Head  Due  to  Friction 


100 


'eet  per  1000  Feet  of  Pipe 


HE 

E 


CHAPTER  XI. 

ACCOUNTS 

ACCURATE  and  detailed  accounts  of  all  funds  received  and 
expended  for  water-works  purposes  should  be  kept  in  suitable 
books,  arranged  in  as  simple  form  as  possible  consistent  with 
an  intelligible  presentation  of  the  facts. 

The  larger  part  of  the  book-keeping  of  a  system  deals  with 
the  accounts  of  the  individual  consumers,  as  receipts  for  water 
supplied  at  meter  or  schedule  rates,  service  connections,  etc., 
and  the  items  are  usually  entered  in  books  to  which  the  name 
registers  has  been  applied. 

Since  the  number  of  bills  rendered  in  the  course  of  a  year  for 
the  several  items  varies  to  a  large  extent,  these  items  may  be 
conveniently  kept  in  three  books,  namely,  a  register  in  which 
all  bills  rendered  for  water  supplied  at  schedule  rates  are  entered, 
a  register  for  meter  accounts,  and  a  service-connection  register. 
The  use  of  one  book  for  all  the  above  purposes  is  inconvenient, 
since  but  one  person  can  have  access  to  the  accounts  at  any  one 
time;  the  amount  of  space  wasted  is  large,  and  the  names  of  the 
consumers  require  rewriting  at  frequent  intervals. 

The  register  containing  the  accounts  of  consumers  to  whom 
water  is  furnished  at  fixed  rates  may  be  arranged  as  follows:  A  line 
extending  across  two  opposite  pages  of  the  book  is  allowed  to 
each  account,  and  the  items  are  entered  in  columns  under  the 
following  headings:  Service  number,  Name,  Address,  and  Rate  for 
year  ending  ....  (or  Rate  for  six  months  ending  ....  ),  the  latter 
column  being  subdivided  under  the  following  headings:  Amount 
of  bill,  Amount  abated,  Amount  paid,  Amount  uncollected,  and 

Date  of  payment.  The  items  included  under  "Rate  for " 

are  repeated  across  the  two  pages  of  the  register  in  order  that  a 

361 


362  MAINTENANCE  AND   OPERATION. 

number  of  successive  bills  may  be  entered  opposite  the  name  of  a 
consumer. 

A  similar  arrangement  may  be  used  for  the  other  registers 
by  changing  the  column  headings  to  conform  to  the  purpose 
for  which  the  book  is  intended. 

Or  the  accounts  may  be  kept  by  the  card  system,  in  which 
case  a  card  is  used  for  each  consumer.  Advantages  derived  from 
the  use  of  cards  for  this  purpose  are:  that  several  clerks  may 

April  1,  1904^ 
WATER    RATE. 


Service  No. 


Amount 


Abatement 


Total 
Paid 


Credit  to 

Water  Maintenance  dcct. 
FIG.  114. — Coupon. 

work  on  the  accounts  at  one  time,  that  changes  due  to  the  moving 
of  consumers  from  one  building  to  another,  etc.,  may  be  adjusted 
more  readily,  and  that  the  paid  and  unpaid  accounts  may  be 
kept  in  separate  files.  Two  disadvantages  of  the  card  system  are 
that  all  figures  must  be  taken  off  in  computation  books  before 
total  amounts  can  be  ascertained,  and  the  liability  that  cards 
may  be  misplaced  or  lost. 

The  bills  are  made  from  the  data  contained  in  the  inspection, 
meter,  and  service  records,  and  all  bills  rendered  by  the  depart- 


ACCOUNTS.  363 


ment  should  have  coupons  attached  upon  which  the  date  of  bill, 
service  number,  name  of  consumer,  amount  of  bill,  etc.,  are  noted. 
These  coupons  are  torn  from  the  bills  by  the  person  to  whom 
payments  are  made,  and  returned  to  the  water-works  office.  In 
order  that  the  coupons  of  bills  made  for  different  purposes  may 
be  easily  distinguished,  the  bills  and  attached  coupons  may  be 
printed  upon  paper  of  different  tints,  or  the  type  or  the  color  of 
ink  used  on  the  coupons  may  be  varied. 

The  amount  of  a  bill  is  entered  in  the  proper  column  of  the 
register  before  the  bill  is  sent  out.  Upon  receipt  of  the  coupon 
from  the  collecting  officer  the  amount  paid  or  abated  is  entered 
in  the  register.  The  total  receipts  on  the  different  accounts  as 
shown  by  the  coupons  are  computed  and  the  results  entered  in 
the  cash-book  or  journal  daily,  weekly,  or  monthly,  as  may  be 
found  convenient.  The  coupons  should  be  preserved  until  the 
accounts  are  made  up  for  the  year,  and  may  then  be  destroyed. 

At  the  close  of  the  fiscal  year  the  total  footings  of  the  columns 
of  the  registers  should  be  ascertained.  The  aggregate  amount 
of  the  bills  rendered  should  equal  the  aggregate  totals  of  the 
various  subdivisions  of  the  register,  and  the  aggregate  amount 
of  the  payments  should  equal  the  totals  of  the  entries  made  in 
the  cash-book  or  journal. 

In  general  all  bills  rendered  by  the  water  department  are 
payable  within  thirty  days,  but  the  instance  is  extremely  rare 
where  all  bills  are  paid  before  the  expiration  of  that  period.  Du- 
plicate bills  are  occasionally  rendered,  but  usually  statements  of 
accounts  due,  or  notices  so  worded  that  the  attention  of  the  delin- 
quents is  called  to  the  fact  that  bills  are  overdue,  are  sent  to  the 
consumers  after  a  reasonable  time  has  elapsed.  In  case  the 
statement  or  notice  does  not  accomplish  its  purpose,  a  shut-off 
notice  is  sent,  and  if  this  notice  is  disregarded  the  supply  is  dis- 
continued until  the  arrears  are  paid. 

The  receipts  from  various  sources  and  the  expenditures  incurred 
for  construction,  maintenance,  and  operation  may  be  kept  in  a 
cash-book,  journal,  and  ledger  of  the  ordinary  form.  Or  sepa- 
rate sets  of  books  may  be  kept  for  the  Construction  and  Main- 
tenance accounts.  Or  in  the  case  of  small  works  where  the 
number  of  detailed  accounts  kept  is  small,  the  entries  may  be 


364 


MAINTENANCE  AND  OPERATION. 


made  in  a  single  book  under  headings  arranged  on  two  pages 
somewhat  as  follows: 


RECEIPTS. 
CONSTRUCTION. 


MAINTENANCE. 


Date. 

Received  from: 

Total 
amount. 

Loans. 

Services. 

Sundry 
acc'ts. 

Schedule 
rates. 

Meter 
rates. 

Sundry 
acc'ts. 

EXPENDITURES. 


CONSTRUCTION. 


Date. 

Paid  to: 

Total 
amount. 

Distribution. 

Services. 

Meters. 

Special. 

MAINTENANCE. 

Administration. 

Pumping. 

Care  of 
appurtenances. 

Repairs. 

Meters. 

Sundry 
acc'ts. 

The  receipt  or  payment  is  entered  in  the  column  headed  '  'Total 
amount,"  and  also  credited  or  charged  to  the  proper  account  as 
indicated  by  the  headings.  The  footings  of  the  columns  are 
carried  forward  from  one  page  to  the  next,  and  the  condition  of 
the  accounts,  or  any  one  account,  can  be  readily  determined 
when  desired. 

All  bills,  particularly  those  for  supplies  and  material  purchased, 
should  be  filed  after  payment  for  future  reference. 

In  order  that  the  data  with  regard  to  items  of  cost  may  be 
accurately  compiled  for  the  various  records  mentioned  in  Chap- 


ACCOUNTS. 


ter  I,  or  for  other  purposes,  both  Force  and  Material  accounts 
should  be  kept.  These  accounts  are  made  daily  and  filed  at 
the  water-works  office  by  the  foremen  or  inspectors  in  charge 
of  the  various  portions  of  the  work.  The  form  shown  below  is 
adapted  for  use  with  a  small  force  working  under  the  direction 
of  a  foreman  or  inspector.  The  blank  forms  are  about  3j"x6" 
and  may  be  carried  conveniently  in  the  pocket  in  a  loose-leaf 
binder  or  in  pads.  The  names  of  the  employes  appear  on  the 
sheet,  the  work  performed  is  noted  in  the  space  at  the  head  of  a 
column,  and  the  time  given  by  each  employe  is  entered  below 


WATER-WORKS  FORCE  ACCOUNT. 


Oct.  10,  1904. 


Leak  10" 
main, 
Pine  Street. 

Repairing 
hydrant 
No.  3, 
Main  Street 

Setting 
meter 
No.  4, 
PineStreet. 

Service 
connection, 
W.  H.  Rice. 

John  Williams,  foreman.  .  . 
Henry  Murray 

5  hrs. 
6    " 
6    " 
6    " 
6    " 

ihr. 
3  hrs. 

3    ' 

|hr. 
i    " 

2J  hrs. 

2      " 

3 

H    Kelley 

J    Smith 

Fred  White 

opposite  the  name.  The  pay-rolls  are  made  from  the  daily  Force 
accounts.  Daily  reports  of  the  amount  of  material  used,  the 
character  of  the  material,  and  where  used,  should  be  made  upon 
prepared  forms  or  upon  the  back  of  the  Force  sheet. 

In  the  case  of  continuous  work,  such  as  extensions  of  mains, 
etc.,  the  time  of  the  individual  laborers  may  be  more  conveniently 
kept  in  a  time-book,  and  the  aggregate  time  entered  on  a  Force 
sheet.  This  time  may  be  apportioned  to  items  such  as  teaming, 
excavation,  pipe-laying,  back-filling,  etc.,  and  data  regarding 
the  progress  of  the  work,  the  material  received,  removed,  or  used, 
should  also  be  given. 

A  Stock  account  is  very  desirable  and  may  be  kept  in  a  book 
prepared  for  that  purpose,  in  which  the  amount,  kind,  and  cost 
of  material  purchased  and  used  is  entered.  At  the  close  of  the 
year  the  figures  should  be  checked  by  making  an  inventory  of  the 
stock  on  hand. 


CHAPTER  XII. 

FINANCIAL  MANAGEMENT. 

To  the  requirements  that  extensions  of,  or  additions  to,  a 
system  of  water- works  be  made  in  accordance  with  good  engineer- 
ing practice,  that  the  efficiency  of  a  system  from  a  mechanical 
standpoint  and  the  sanitary  quality  of  the  supply  be  maintained 
or  improved,  should  be  added  the  requirement  that  the  depart- 
ment be  operated  on  a  business  basis.  In  general,  conditions 
favorable  to  such  operation  more  often  obtain  in  works  owned 
and  operated  by  private  companies  than  when  these  are  strictly 
municipal  enterprises.  Even  in  the  latter  instances,  however, 
the  affairs  of  the  department  may  be  conducted  in  a  business- 
like manner  if  political  or  personal  interests  are  eliminated. 

At  the  outset  a  distinction  should  be  made  between  funds 
expended  and  obtained  for  purposes  of  construction  and  of  main- 
tenance. The  cost  of  the  original  works  is  charged  to  the  Con- 
struction account,  and  expenditures  for  extensions,  additions, 
or  improvements  are  also  properly  chargeable  to  that  account. 
Under  this  heading  are  included  the  cost  of  new  mains  and 
appurtenances,  services,  meters,  pumping  machinery,  reservoirs 
or  stand-pipes,  filtration  works,  and  expenditures  incurred  for 
the  improvement  or  extension  of  the  source  of  supply. 

Expenditures  for  the  purpose  of  renewing  portions  of  the 
system,  such  as  mains  and  appurtenances,  pumping  machinery  ? 
etc.,  which  are  either  worn  out  or  of  insufficient  capacity,  are 
usually  charged  to  the  Construction  account.  Current  practice 
is  in  this  respect,  however,  varied.  In  some  cases  the  cost  of 
renewing  minor  portions  of  the  works,  as  small  mains,  services, 
and  meters,  is  charged  to  the  Maintenance  account  or  is  divided 
between  the  two  general  accounts.  In  any  case  it  is  advisable 

366 


F1N/1NCI/IL   MANAGEMENT.  367 

that  the  accounting  of  renewals  be  made  in  such  manner  that 
expenditures  for  original  construction  and  for  renewals  may  be 
distinguished  from  each  other. 

Funds  for  purposes  of  construction  are  usually  provided  by 
the  issue  of  bonds  or  notes.  When  the  works  are  owned  by  the 
municipality,  these  bonds  or  notes  bear  interest  at  certain  speci- 
fied rates,  usually  3  or  4  per  cent  per  annum,  and  are  payable 
at  a  stated  time,  usually  ten,  twenty,  or  thirty  years,  after  the 
date  of  issue.  In  some  municipalities  the  cost  of  extensions  is 
paid  from  assessments  upon  abutting  property. 

Minor  items  of  construction,  as  yearly  expenditures  for  new 
service  connections  or  meters,  are  often,  although  charged  to 
the  Construction  account,  paid  for  from  the  surplus  annual 
revenues. 

Extensions  of  existing  works  which  have  as  their  object  the 
improvement  of  the  efficiency  of  the  system  are  often  made  with- 
out regard  to  any  financial  benefit  which  would  be  directly  derived 
therefrom.  Such  is  not  usually  the  case,  however,  when  mains 
are  extended  in  new  streets,  in  streets  not  previously  supplied 
with  water,  or  in  private  ways.  Mains  are  not  generally  laid 
in  public  streets  unless  the  revenue  to  be  received  from  the  sale 
of  water  will  yield  a  fair  return  upon  the  investment.  When 
the  revenue  based  on  the  established  schedule  of  rates  is  insuffi 
cient  for  this  purpose,  and  the  indications  are  that  sufficient 
revenue  may  be  received  in  the  near  future,  extensions  are  occa- 
sionally made,  provided  the  water-takers  served  by  the  particular 
extension  agree  to  pay,  as  special  water  rates,  a  sum  equivalent 
to  the  fair  return  for  a  stated  period  of  time.  These  special 
rates  are  fixed  to  produce  an  income  of  from  4  to  7  per  cent 
annually  on  the  cost  of  the  work.  Where  extensions  are  made 
in  private  ways,  the  entire  cost  of  the  work  is  usually  borne  by 
the  parties  benefited,  although  provision  may  be  made  that  the 
cost  be  refunded  at  such  time  as  the  ways  become  public. 

The  cost  of  service  connections  outside  street  limits  is  borne 
by  the  consumers.  The  cost  of  connections  within  street  limits 
is  in  some  cities  and  towns  assumed  by  the  department;  in  others 
a  stated  sum  varying  with  the  size  of  connection  is  charged.  As 
a  general  rule,  service  connections  are  not  laid  unless  the  revenue 


368  MAINTENANCE  AND  OPERATION. 

to  be  derived  therefrom  is  at  least  equal  to  the  established  annual 
rate  for  a  single  faucet. 

Water-meters  should  be  owned  and  controlled  by  the  water 
department,  and  not  by  the  individual  consumers.  The  cost  of 
meters  is  ultimately  borne  by  the  consumers  in  either  event, 
and  meters  may  be  removed  for  testing  or  repairs,  or  replaced, 
with  less  friction  between  the  department  and  the  consumers  in 
the  former  instance  than  would  be  the  case  in  the  latter. 

All  expenditures  incurred  for  the  maintenance  and  operation 
of  a  system  of  water- works  are  charged  to  the  Maintenance  account. 
The  items  of  expenditure  included  in  this  account  are  the  salaries 
of  administrative  and  executive  officials,  office  expenses,  wages 
of  permanent  employes,  pumping  expenses,  purification  expenses, 
care  and  repair  of  the  system;  in  brief,  all  expenditures  incurred 
in  maintaining  the  system  in  good  condition  and  for  its  opera- 
tion. The  annual  interest  charges  on  outstanding  bonds  or 
notes  are  also  paid  from  the  Maintenance  account.  In  addi- 
tion, payments  to  a  sinking-fund  which  shall  be  sufficient  to  pay 
the  outstanding  indebtedness  when  it  becomes  due  are  made 
from  this  account,  where  the  works  are  owned  by  the  municipality. 
Where  works  are  owned  by  private  companies,  similar  annual  pay- 
ments may  be  made  to  a  depreciation  fund,  as  a  provision  for 
the  replacement  of  portions  of  the  system  when  this  becomes 
necessary.  In  this  latter  instance  a  reasonable  profit  in  addi- 
tion to  the  foregoing  charges  is  to  be  desired. 

The  funds  required  to  provide  for  the  varied  expenditures  for 
maintenance  and  operation  are  derived  from  the  receipts  from 
the  sale  of  water,  minor  receipts  for  repairs  and  the  sale  of  mate- 
rial, and  from  the  general  tax  levy.  These  receipts  constitute 
the  Income  account.  The  principal  sources  of  revenue  are  the 
water  rates  and  the  appropriation  from  the  tax  levy,  and 
the  proportion  of  the  annual  income  derived  from  the  former, 
as  compared  with  that  derived  from  the  latter,  is  subject  to 
variation  within  wide  limits  in  different  communities. 

Primarily  the  water  rates  represent  the  value  of  the  water 
actually  or  presumably  used  by  the  individual  consumers,  and 
the  appropriation  in  a  measure  represents  the  value  of  the  fire 
protection  and  other  indirect  benefits  afforded  by  the  works. 


FINANCIAL   MANAGEMENT.  369 

The  several  departments  of  a  municipality  should  be  considered 
upon  the  same  basis  as  private  persons,  and  the  water  depart- 
ment should  receive  funds  in  the  form  of  cash  payments  or  credits 
for  all  water  supplied  for  municipal  purposes.  This  includes 
water  used  in  public  buildings,  fountains,  for  sewer  flushing, 
street  sprinkling  and  cleaning. 

Water  rates  are  divided  into  two  general  classes:  schedule, 
fixed,  or  assessed  rates,  and  meter  rates.  The  former  are  based, 
not  upon  the  amount  of  water  actually  used,  as  are  the  latter, 
but  upon  the  amount  presumably  used,  the  convenience  or  luxury 
derived  from  the  practically  unlimited  use  of  the  supply,  the 
opportunity  afforded  for  the  waste  of  water,  or  a  combination 
of  these  items.  The  methods  by  which  the  amount  of  the  annual 
rate  is  ascertained  in  a  given  instance  differ  widely  in  practice. 
In  general,  schedule  rates  are  based  upon  one  or  more  of  the  fol- 
lowing items:  size  of  lot,  street  frontage,  assessed  value  of  build- 
ing supplied,  number  of  persons  supplied,  number  of  rooms, 
number  and  kind  of  fixtures,  and  annual  rental  value  of  premises. 
In  the  majority  of  works  the  rate  annually  assessed  upon  a  build- 
ing or  apartment  occupied  by  a  single  family  is  limited  by  a  so- 
called  maximum  rate,  which  is  usually  from  fifteen  to  twenty- 
five  dollars. 

Rates  for  metered  water  are  either  uniform,  i.e.,  one  price  per 
unit  of  quantity  regardless  of  the  amount  consumed,  or  vary 
with  the  quantity  furnished.  In  this  latter  case  a  certain  price 
per  unit  quantity  is  charged  for  the  supply  up  to  a  definite 
amount,  and  reduced  rates  are  charged  for  excess  quantities. 
The  following  is  an  example  of  a  graduated  schedule  of  this 
kind: 
For  quantities  not  exceeding  3000  cubic  feet  per  quarter, 

per  100  cubic  feet So. 20 

Excess  above  3000  up  to  10,000  cubic  feet  per  quarter, 

per  100  cubic  feet o .  15 

Excess  above  10,000  up  to  50,000  cubic  feet  per  quarter, 

per  100  cubic  feet o .  10 

Excess  above  50,000  cubic  feet  per  quarter,  per  100  cubic 

feet o .  075 

A   graduated   scale   which   offers   any   inducement    for   con- 


370  MAINTENANCE   AND   OPERATION. 

sumers  to  waste  water  should  never  be  established.     A  schedule 
of  this  character  would  read  somewhat  as  follows: 
For  quantities  not  exceeding  3000  cubic  feet  per  quarter, 

per  TOO  cubic  feet $o .  20 

For  quantities  not  exceeding  10,000  cubic  feet  per  quarter, 

per  100  cubic  feet o .  15 

For  quantities  not  exceeding  50,000  cubic  feet  per  quarter, 

per  100  cubic  feet o .  10 

For  quantities  exceeding  50,000  cubic  feet  per  quarter,  per 

100  cubic  feet o .  075 

Under  a  schedule  of  this  form  a  consumer  would,  in  cases 
when  the  consumption  approached  one  of  the  limits  given,  be 
inclined  to  waste  water  in  excess  of  that  limit  in  order  to  realize 
the  benefit  of  the  lower  rate. 

Whenever  water  is  sold  by  measure,  a  definite  sum  is  fixed 
as  the  minimum  annual  rate  regardless  of  the  actual  registra- 
tion of  the  meter.  The  minimum  rates  established  in  different 
works  range  from  about  five  to  fifteen  dollars  per  year.  Two 
principal  reasons  for  the  establishment  of  a  minimum  rate  are 
advanced.  The  first,  which  maybe  termed  the  financial  reason, 
is  that  a  certain  amount  of  money  is  required  each  year  to  meet 
the  fixed  charges  of  maintenance  and  operation,  including  inter- 
est charges  and  sinking-fund  requirements.  The  interest  on 
outstanding  bonds,  sinking-fund  payments,  the  salaries  of  per- 
manent officials  and  employes,  and  the  cost  of  repairs  are  affected 
but  slightly,  if  at  all,  by  variations  in  the  total  amount  of  water 
annually  furnished.  By  the  collection  of  minimum  rates,  funds 
applicable  to  the  partial  payment  of  these  fixed  charges  are 
assured.  The  second  reason  is  that  as  a  sanitary  measure  exces- 
sive economy  in  the  use  of  water  should  not  be  encouraged,  and 
under  the  minimum  rates  in  use  an  ample  supply  for  an  average 
family,  if  waste  be  restricted,  may  be  obtained  for  all  domestic 
purposes.  Established  rates  for  water  supplied  by  meter  measure- 
ment to  domestic  consumers  range  from  twenty  to  thirty  cents 
per  thousand  gallons,  or  about  fifteen  to  twenty-five  cents  per 
one  hundred  cubic  feet. 

In  an  ideal  system  the  annual  revenue  from  rates  and  the 
appropriation  should  equal  the  annual  expenditures  plus  the 


FINANCIAL   MANAGEMENT.  371 

contribution  to  the  sinking-  or  depreciation-fund  and  the  inter- 
est on  the  outstanding  bonds  or  notes;  the  cost  of  the  service 
should  be  equitably  divided  between  the  consumers  and  the 
taxpayers,  and  the  rates  should  be  equitably  apportioned  among 
the  individual  consumers.  This  result  can,  however,  be  only 
approximately  realized  under  the  most  favorable  conditions. 
Usually  the  annual  receipts  from  the  sale  of  water  show  an  in- 
crease year  by  year,  and  the  surplus  revenue  is  used  to  make  larger 
contributions  to  the  sinking-  or  depreciation-fund.  Or  the  amount 
of  the  hydrant  rental  or  contribution  from  the  general  tax  levy  is 
diminished. 

In  addition  to  the  direct  benefits  which  the  water-takers 
of  a  community  receive  from  a  system  of  water-works,  the  instal- 
lation of  works  of  this  kind  results  in  more  or  less  indirect  bene- 
fit to  both  consumers  and  taxpayers.  In  consequence  of  the 
existence  of  water-pipes  in  the  public  streets,  real  estate  abut- 
ting on  these  streets  is  increased  in  value,  the  rental  value  of  tene- 
ments and  apartments  supplied  with  water  is  likewise  enhanced, 
and  a  saving  in  fire-insurance  premiums  is  effected.  The  capacity 
of  a  system  of  water-works  is  increased,  often  to  considerable 
extent,  to  provide  for  the  large  rates  of  flow  necessary  for  efficient 
fire  protection,  and  also  as  a  provision  for  future  demands,  above 
the  ordinary  requirements  of  a  community  for  domestic  and 
manufacturing  purposes.  A  certain  proportion  of  the  annual 
expenditures  may,  therefore,  be  equitably  assessed  upon  taxable 
property.  According  to  various  authorities,  the  provisions  for 
fire  protection  increase  the  cost  of  a  system  of  works  about  one- 
third.  The  expenditures  for  maintenance  and  operation  are 
likewise  somewhat  increased,  hence  it  is  assumed  that  50  per 
cent  of  these  expenditures,  including  interest  and  sinking-fund 
charges,  may  be  taken  as  an  approximate  measure  of  the  value 
of  the  fire  protection  and  other  indirect  benefits  afforded  by  the 
works,  and  may  be  properly  raised  by  general  taxation.  The 
remaining  50  per  cent  of  the  annual  expenses  may  then  be  appor- 
tioned among  the  individual  consumers.  The  equitable  division 
of  this  portion  of  the  expenditures  is  best  accomplished  by  the 
use  of  meters. 

The  method  for  the  apportionment  of  the  cost  of  maintain- 


372  MAINTENANCE   AND   OPERATION. 

ing  and  operating  a  system  of  water-works  outlined  above  is 
rarely  followed  in  practice  at  present,  particularly  in  the  estab- 
lishment of  a  schedule  of  water  rates  for  new  works.  It  is,  how- 
ever, of  value  in  the  adjustment  of  existing  schedules.  Rates 
established  in  accordance  with  the  method  outlined  are  based 
both  upon  the  cost  and  the  value  of  the  service,  and  these  two 
factors  constitute  the  only  proper  and  reasonable  basis  for  such 
establishment.  Since  the  cost  of  service  is  affected  principally 
by  the  local  conditions  which  obtain  in  a  given  case,  and  the  inter- 
est charges  and  sinking-  or  depreciation-fund  requirements  de- 
pend upon  the  cost  of  construction,  the  cost  of  service  may  be 
widely  different  in  any  two  communities.  This  difference  is 
particularly  marked  if  comparisons  are  made  between  works 
respectively  supplied  by  gravity  and  by  pumping.  Rates  estab- 
lished by  the  method  indicated  would,  when  based  upon  the  cost 
of  maintaining  and  operating  a  new  system  with  a  comparatively 
small  number  of  consumers,  be  excessive  and  the  increase  in 
new  business,  in  consequence,  limited.  Furthermore,  the  aver- 
age consumer  pays  little  or  no  attention  to  the  cost  of  deliver- 
ing water  upon  his  premises,  but  bases  his  criticisms  with  regard 
to  the  reasonableness  of  rates  upon  comparisons  made  with 
schedules  which  obtain  in  adjacent  cities  or  towns.  It  is  the 
usual  custom,  therefore,  when  a  supply  of  water  is  introduced 
in  a  city  or  town,  to  base  the  schedule  of  rates  in  large  measure 
upon  the  schedules  in  use  in  works  in  close  proximity  to  the 
case  at  hand.  The  yearly  deficit  is  then  made  up  by  appro- 
priations from  the  general  tax  levy,  and  during  the  first  years 
of  operation  the  payments  to  the  sinking-fund  are  small.  The 
appropriation  from  the  general  funds  of  a  municipality  for  water- 
works purposes  is  usually  made  in  the  form  of  hydrant  rental, 
i.e.,  a  specified  sum  is  paid  for  each  public  hydrant  connected 
with  the  works. 

Since  funds  are  necessary  at  all  seasons  of  the  year  for  the 
payment  of  bills  incurred  by  the  department,  it  is  customary 
to  collect  the  whole  or  a  portion  of  the  water  rates  in  advance. 
Bills  for  water  furnished  at  schedule  rates  are  usually  rendered 
annually  or  semi -annually,  and  are  payable  in  advance.  Where 
water  is  furnished  at  such  rates,  the  total  annual  revenue  to  be 


FINANCIAL   MANAGEMENT.  373 

received  for  a  given  year  may  be  quite  closely  computed,  and 
this  fact  constitutes  the  chief  advantage  of  this  method  of  assess- 
ment. On  the  contrary,  the  revenue  to  be  derived  from  the 
sale  of  water  by  meter  measurement  is  often  very  uncertain. 
The  minimum  rates  may  be  collected  in  advance,  but  the  total 
receipts  can  only  be  approximately  ascertained  until  the  close 
of  the  fiscal  year.  Meter  bills  are  usually  rendered  quarterly 
or  semi- annually  to  domestic  consumers,  and  monthly  or  quarterly 
to  manufacturers  or  other  large  consumers. 

Water  furnished  for  manufacturing  purposes  is  usually  metered, 
and  the  rates  at  which  it  is  sold,  when  the  domestic  consumption 
is  not  metered,  are,  in  general,  arbitrarily  fixed.  With  a  view  to 
the  encouragement  of  manufacturing  enterprises  the  meter  rates, 
particularly  when  on  a  graduated  scale,  are  often  made  purposely 
low.  In  such  instances  a  change  from  the  schedule  to  the  meter 
system  of  furnishing  water  to  domestic  consumers  results  in  a 
decrease  in  the  annual  revenue  unless  the  schedule  is  revised. 
Owing  to  this  fact,  due  consideration  should  be  given  to  the  cost 
of  delivering  water,  when  manufacturing  rates  are  established, 
in  order  that  radical  changes  in  the  schedule  may  be  avoided  when 
the  domestic  consumption  is  also  metered. 

The  proposition  is  often  advanced  that  when  water  is  fur- 
nished by  measurement  all  consumers  should  be  treated  alike 
and  on  an  equal  basis,  regardless  of  the  quantities  consumed, 
i.e.,  the  water  should  be  furnished  at  a  uniform  rate  per  unit 
quantity.  An  adherence  to  a  uniform  meter  rate  would  in  many 
cases  cause  large  consumers  to  obtain  water  from  sources  other 
than  the  public  supply,  to  the  financial  disadvantage  of  the 
department.  Such  conditions  may  also  obtain  that  the  quantities 
used  by  a  few  consumers  constitute  a  considerable  proportion 
of  the  total  consumption,  and  therefore  a  material  reduction  in 
the  unit  cost  of  delivering  water  results.  Under  a  uniform 
schedule  the  small  consumers  would  then  receive  the  benefit  of 
the  reduced  cost.  In  general,  the  adoption  of  a  graduated  scale 
is  consistent  with  good  business  policy,  and  such  schedules, 
if  good  judgment  is  exercised  in  their  establishment,  do  not 
favor  large  consumers  at  the  expense  of  the  small  or  domestic 
consumers. 


374  MAINTENANCE  AND   OPERATION. 

An  established  schedule  of  rates  should  not  be  changed  unless 
the  results  obtained  from  a  study  of  the  financial  and  physical 
condition  of  the  works,  present  and  prospective,  indicate  the 
necessity  for  or  advisability  of  such  change.  In  lieu  of  a  gen- 
eral reduction  in  rates,  discounts  are  allowed  in  some  works  on 
all  bills  paid  within  a  specified  time  after  they  are  due.  This 
discount  is  usually  in  the  form  of  a  percentage;  as,  ten  per  cent 
of  the  amount  of  the  bill  if  the  same  is  paid  within  ten  days  from 
date,  and  five  per  cent  if  paid  within  twenty  days.  If  unfore- 
seen events  necessitate  changes  in  the  schedule,  the  changes  may 
be  more  readily  effected  under  a  discount  sys  em  than  under 
a  fixed-rate  system.  Although  in  all  well-managed  works  the 
loss  from  non-payments  of  rates  is  insignificant  in  amount,  more 
or  less  time  is  used  and  friction  occasioned  in  the  collection  of 
overdue  water  rates,  hence  cash  customers  may  very  properly 
be  given  the  benefits  arising  from  the  discount  plan. 

A  change  from  the  schedule  to  the  meter  basis  of  rate  assess- 
ment, with  the  accompanying  general  introduction  of  meters, 
in  an  established  system  of  works  is  usually  productive  of  the 
following  results: 

First,  an  increase  in  the  expenditures  for  clerical  and  re- 
pair work,  inspection,  and  interest  and  sinking-fund  charges. 

Second,  a  decrease  in  the  expenditures  for  fuel,  and  possibly 
to  a  slight  extent  in  the  other  pumping  expenses  when  water  is 
pumped. 

Third,  a  decrease  in  the  revenue  from  consumers,  or, 

Fourth,  a  redistribution  of  the  charges  for  water  furnished 
individual  consumers. 

If  the  decrease  indicated  in  the  second  item  exceeds  the  in- 
crease due  to  the  first,  the  change  is  advantageous  to  both  depart- 
ment and  consumers.  Such,  however,  is  not  the  result  ordinarily 
obtained.  However,  the  diminution  in  the  annual  consumption 
resulting  from  the  introduction  of  meters,  considered  in  a  pre- 
vious chapter,  may  be  advantageous  if  expenditures  for  addi- 
tional construction  or  for  purification  are  materially  reduced 
thereby.  If  the  annual  income  is  just  sufficient  to  meet  the 
charges  for  maintenance  and  operation,  a  reduction  in  the  amount 
of  revenue  is  not  desirable,  and  the  fixed  charges  cannot  be  met 


FIN 'A 'NCI A L   MANAGEMENT.  375 

by  a  uniform  minimum  rate  charge  unless  that  charge  be  exces- 
sive. As  a  means  of  providing  revenue  sufficient  to  meet  the 
fixed  charges  the  graduated  minimum  rate  method  used  by 
Mr.  Freeman  C.  Coffin,  C.E.,  is  of  value.  The  minimum  rates 
established  by  this  method,  and  the  quantity  of  water  furnished 
to  a  consumer  under  these  rates,  vary  with  the  kind  of  fixtures 
supplied  from  the  metered  service  connection.  The  minimum 
meter  rates  established  at  Merrimac,  Mass.,  afford  an  illustra- 
tion of  the  use  of  a  graduated  minimum  scale.  In  these  works 
a  minimum  charge  of  six  dollars  per  year  is  made  where  ordinary 
faucets  only  are  supplied,  eleven  dollars  per  year  for  faucets  and 
water-closets,  fifteen  dollars  per  year  for  faucets,  water-closets, 
and  bath-tubs,  and  twenty  dollars  per  year  for  the  above  fix- 
tures with  hose,  etc.  This  latter  charge  is  the  highest  minimum 
charge  made  for  water  supplied  to  a  single  family.  The  minimum 
charges  are  payable  quarterly  in  advance,  and  excess  bills  based 
upon  the  regular  schedule  are  rendered  at  the  end  of  each  quarter. 
Provision  for  the  cost  of  maintaining  meters  is  made  in  some 
works  by  the  collection  of  meter  rentals.  An  ordinary  service- 
meter  set  in  place  costs  from  ten  to  sixteen  dollars.  The  expense 
of  maintaining  these  small  meters  is  about  as  follows: 

Interest  on  first  cost  at  4%  per  annum $o .  40  to  $o .  84 

Contribution  to  sinking-  or  depreciation-fund,  4%  of  cost.  .      0.40  to    0.84 
Annual  maintenance:    reading,  inspection,  testing,  repairs, 

and  clerical  work i .  oo         i .  oo 

Total  annual  maintenance $r .  80  to  $2  .68 

At  the  expiration  of  twenty  years  the  sinking-fund  will  be 
sufficient  to  pay  the  original  cost  of  the  meter  or  to  replace  it, 
and  the  life  of  an  average  meter  is  usually  assumed  to  be  equal 
to  that  period.  Since  this  life  is,  in  general,  dependent  upon 
the  character  and  amount  of  water  passed  through  the  meter, 
the  duration  of  service  of  a  meter  may  be  more  or  less  than 
twenty  years.  Within  this  limit  the  items  of  maintenance  affected 
by  the  amount  of  water  consumed  through  a  metered  service  are 
those  of  repair  and  testing  only,  and  since  these  are  a  small  pro- 
portion of  the  total  annual  expense,  the  cost  of  maintaining 
meters  may  be  equitably  divided  equally  among  the  individual 


MAINTENANCE  AND  OPERATION. 

consumers  without  regard  to  the  amount  of  water  furnished. 
The  sum  of  two  dollars  per  meter  is,  therefore,  usually  charged 
for  the  annual  rental  of  an  ordinary  service-meter.  This  sum  is 
ncreased  with  the  increase  in  size  of  the  meter  in  proportion  to 
the  additional  interest,  sinking-fund,  and  repair  charges.  A 
further  charge  is  at  times  included  in  the  rental  of  large  meters 
to  provide  for  the  amount  of  water  which  may  pass  these  meters 
without  registration.  This  charge  corresponds  to  the  value  of 
the  possible  unrecorded  flow  at  the  established  rates. 

The  following  charges  may  then  be,  and  are  usually,  made 
when  water  is  furnished  through  metered  service  connections: 

First,  an  annual  rental  depending  upon  the  size  of  meter 
which  will  meet  the  expense  of  its  maintenance,  and  also  pro- 
vide for  the  under-registration  of  large  meters  at  small  rates 
of  flow. 

Second,  a  minimum  annual  rate  which  shall  provide  in  a 
measure  for  the  fixed  charges  for  the  maintenance  and  operation 
of  the  works,  and  which  shall  prevent  undue  economy  in  the 
use  of  water  for  domestic  purposes. 

Third,  a  graduated  scale  of  rates  for  metered  water. 


CHAPTER  XHI. 
RULES  AND  REGULATIONS. 

RULES  and  regulations  governing  the  use  of  water  are  usually 
prescribed  by  the  water  commissioners  where  the  works  are 
owned  by  a  municipality,  and  by  the  company  when  these  are 
private  enterprises.  Such  rules  and  regulations  as  are  estab- 
lished, or  a^e  in  use,  should  be  explicit  and  should  be  impar- 
tially enforced.  A  limited  number  of  rules  which  are  avail- 
able in  printed  form,  and  are  strictly  enforced,  are  of  more  value 
in  the  management  of  water-works  than  a  large  number  of  regu- 
lations inscribed  in  records  and  forgotten  or  rarely  observed  by 
the  parties  concerned. 

The  following  directions  and  reservations  are  commonly 
included  in  the  rules  established  by  various  works. 

An  application  for  a  supply  of  water  is  required  to  be  made 
upon  a  prepared  form  and  signed  by  the  owner  of  the  property 
supplied  or  his  agent. 

In  some  works  the  material  and  labor  required  for  making 
a  service  connection  is  furnished,  and  the  connection  made  by  the 
department  from  the  street  main  to  the  stop-  and  waste-cock  in 
the  cellar  of  the  applicant's  building.  In  other  works  the  pipe  is 
furnished  and  laid  with  the  necessary  appurtenances  by  the  de- 
partment to  the  street  line  only,  all  work  beyond  the  street  line 
being  performed  by  plumbers.  Or  the  entire  work  is  performed 
by  licensed  plumbers,  although  in  some  cases  the  street  main  is 
tapped  by  employes  of  the  department.  Where  any  portion  of 
the  work  of  making  a  service  connection  is  performed  by  plumbers, 
permits  are  issued  by  the  department  covering  each  connection 
made,  returns  upon  prepared  forms  of  the  service  and  fixtures 
connected  therewith  are  required,  and  the  work  is  inspected  by 

377 


MAINTENANCE  AND   OPERATION. 

employes  of  the  department  before  it  is  concealed.  The  size 
of  pipe,  and  the  material  of  the  pipe  and  fittings  to  be  used,  are 
usually  specified  by  the  department. 

The  method  of  making  service  connections,  and  the  charges 
to  be  borne  by  the  applicant  therefor,  should  be  clearly  stated 
in  the  rules  and  regulations. 

When  the  entire  service  connection  from  the  street  main  to 
the  building  supplied  is  laid  by  the  department,  plumbers  or 
other  unauthorized  persons  are  not  allowed  to  disturb  in  any 
manner  the  pipe  or  fittings  placed  by  the  department. 

Notice  of  alterations  in,  or  additions  to,  the  fixtures  origi- 
nally supplied  is  required  from  the  water-taker  or  the  plumber 
doing  the  work.  In  some  works  no  notice  is  required  where 
alterations  made  consist  merely  in  the  replacement  of  a  fixture 
by  another  of  the  same  class. 

Unnecessary  waste  of  water  is  prohibited,  and  water-takers 
are  required  to  maintain  the  interior  piping  and  fixtures  con- 
nected thereto  in  good  condition  and  repair. 

Consumers  are  not  allowed  to  furnish  water  to  persons  not 
entitled  to  its  use,  nor  to  conceal  the  purposes  for  which  water 
is  used. 

Where  service  connections  are  not  metered,  the  use  of  hose 
for  sprinkling  street  or  lawns  or  for  irrigating  gardens  is  usually 
restricted.  Regulations  restricting  the  use  of  hose  are  more  readily 
enforced  if  the  hour  or  hours  of  the  day  during  which  such  use 
is  permissible  are  stated  explicitly. 

When  meters  are  owned  by  the  department  and  are  located 
in  buildings,  consumers  are  usually  held  responsible  for  damage 
to  the  meter  due  to  their  negligence  or  to  freezing.  Consumers 
are  also  required  to  protect  pipes  and  fixtures  on  their  premises 
from  freezing. 

The  times  at  which  bills  are  rendered  and  are  due  are  stated, 
and  when  several  tenants  are  supplied  through  a  single  service- 
pipe  the  property-owner  is  held  responsible  for  the  water  rates. 

When  water  is  furnished  at  schedule  rates,  discounts  or  abate- 
ments are  usually  allowed,  provided  that  notice  is  given  when 
premises  are  vacant  in  order  that  the  water  may  be  shut  off  if  the 
department  so  desires,  and  that  fixtures  not  in  use  may  be  sealed. 


RULES  AND  REGULATIONS.  379 

Officials  or  employes  of  the  works  are  allowed  to  enter  the 
premises  of  water-takers  at  all  reasonable  times  to  inspect  the 
service,  and  to  test,  repair,  or  replace  meters. 

The  supply  of  water  may  be  interrupted  in  case  it  becomes 
necessary  to.  shut  off  a  main  for  repairs  or  other  purposes.  Pre- 
vious notice  of  such  interruption  is  usually  given  whenever  pos- 
sible. 

The  water  is  usually  shut  off  from  the  premises  of  any  taker 
who  fails  to  comply  with  the  rules  and  regulations  or  neglects 
to  pay  water  rates  after  having  been  notified  to  do  so.  In  these 
instances  a  charge  is  usually  made  for  letting  on  the  water  after 
the  cause  for  complaint  has  been  removed. 

The  department  usually  reserves  the  right  to  place  a  meter 
upon  a  service  and  to  charge  for  water  supplied  at  meter  rates. 

When  connections  are  desired  for  purposes  ot  fire  protection, 
detailed  plans  ot  the  location  of  all  pipes,  valves,  hydrants,  etc., 
are  required.  All  outlets  from  connections  of  this  nature  are 
sealed,  the  seals  to  remain  unbroken  except  in  case  ot  fire  or  when 
water  is  used  for  tests,  unless  the  connection  is  metered  or  pro- 
vided with  other  devices  for  indicating  a  flow  of  water  through 
the  pipes.  Connections  between  the  fire- pipes  and  those  in  ordi- 
nary use  are  not  allowed. 


CHAPTER  XIV. 

ANNUAL  REPORTS. 

THE  water  commissioners  of  a  city  or  town  which  is  provided 
with  a  public  water-works  system  annually  present  to  the  munici- 
pality a  report  regarding  the  system  under  their  direction  and  con- 
trol, in  accordance  with  the  provisions  of  legislative  acts,  municipal 
ordinances,  or  as  a  result  of  established  custom.  These  annual 
reports  should  furnish  information  concerning  the  condition  of 
the  works,  financial  and  otherwise,  the  amount  and  nature  of 
the  work  performed  during  the  period  covered  by  the  report, 
recommendations  with  regard  to  any  action  that  the  municipality 
should  take,  and  facts  which  will  enable  the  community  to  deal 
intelligently  with  the  recommendations  made. 

A  brief  statement  of  the  financial  condition  of  the  works  is 
usually  presented  in  the  reports.  This  statement  should  show 
the  cost  of  the  works,  the  amount  of  the  outstanding  bonds  or 
notes,  the  amount  of  the  sinking-fund,  and  the  net  debt  at  the 
date  the  report  is  made.  The  work  performed  for  purposes  of 
construction  should  be  briefly  described,  and  if  any  portion  of 
this  work  has  been  done  by  contract,  information  with  regard 
to  the  nature  of  the  work,  the  name  of  the  firm  or  individual 
to  whom  the  contract  was  awarded,  the  amount  of  the  contract, 
and  the  progress  made,  is  usually  given.  When  competitive 
bids  are  received  a  summary  of  the  bids  may  be  included. 

Statements  with  regard  to  the  extensions  of  main  pipes  and 
services,  and  the  additional  hydrants,  valves,  meters,  etc.,  placed 
during  the  year,  may  be  made  in  tabular  iorm,  similar  to  the 
forms  followed  in  the  construction  records.  Alterations  in  or 
renewals  of  any  parts  of  the  existing  works  should  be  treated 
in  similar  manner.  The  tabulations  may  be  supplemented  by 

380 


ANNUAL  REPORTS.  381 

~^^  . 

such  explanatory  matter  as  it  may  appear  necessary  or  advisable 
to  append  thereto.  Data  with  regard  to  the  total  amount  of 
pipe  of  the  several  diameters,  the  total  number  of  valves,  hydrants, 
service  connections,  and  meters  of  the  several  patterns  and  sizes 
in  use,  are  to  be  desired. 

The  recorded  results  of  such  observations  as  are  made  of  the 
precipitation  on  the  catchment  area,  the  yield  of  this  area,  or  the 
flow  of  streams,  and  the  meteorological  observations,  should  be 
presented  in  more  or  less  detail.  Data  with  regard  to  the  con- 
sumption of  water  and  the  operation  of  pumping  or  purification 
plants  should  also  be  given. 

The  annual  financial  statements  should  be  made  with  a  view 
to  the  preservation  of  data  of  value  or  interest  to  the  department 
and  the  community  rather  than  to  the  gratification  of  the  curi- 
osity of  a  few  inquisitive  individuals.  The  sums  received  from 
various  general  sources  and  the  expenditures  for  construction, 
maintenance,  and  operation  should  be  stated  in  concise  form. 
Financial  statements  covering  pages  of  detail  regarding  the 
amounts  paid  various  persons  or  corporations  for  labor,  mate- 
rials, etc.,  are  of  little  value  as  compared  with  summarized  state- 
ments of  total  expenditures  for  pumping,  purification,  repairs, 
maintenance  of  meters,  hydrants,  etc.  Summarized  statements  of 
the  cost  of  maintaining  and  operating  water-works  make  the 
reports  of  value,  not  only  to  the  municipality  served  by  the 
works  in  question,  but  to  the  water  departments  of  other  cities 
and  towns. 

Water-works  officials  may  derive  much  of  benefit  at  times 
from  the  reports  of  other  works,  particularly  if  data  upon  different 
subjects  can  be  compared  upon  a  uniform  basis.  Means  for  such 
comparison  are  afforded  by  the  use  of  established  forms,  and 
the  form  for  statistics  adopted  by  the  New  England  Water- works 
Association  is  now  used  by  a  number  of  public  water  departments. 
This  form  is  given  on  the  following  pages. 


382  MAINTENANCE  AND  OPERATION. 

SUMMARY   OF   STATISTICS 

FOR  THE  YEAR  ENDING 

In  form  recommended  by  the  New  England  Water- works  Association. 


WATER-WORKS. 

(City  or  Town.)  (County.)  (State.) 

GENERAL  STATISTICS. 

Population  by  Census  of  1 9     , 

Date  of  construction, 

By  whom  owned 

Source  of  supply, 

Mode  of  supply  (whether  gravity  or  pumping) , 


PUMPING  STATISTICS. 


i.  Builders  of  Pumping  Machinery,  .  . 

a.  Kind, 

b.  Brand  of  coal,, 


2.  Description  of 
fuel  used, 


c.   Average  price  of  coal  per  gross  ton,  delivered,  $ .... 


d.  Percentage  of  ash, 

[  e.   Wood,  price  per  cord,  $ 

3.  Coal  consumed  for  the  year, Ibs. 

4.  [Pounds  of  wood  consumed]-f-3  =  equivalent  amount  of  coal, Ibs. 

4<z.  Amount  of  other  fuel  used, 

5.  Total  equivalent  coal  consumed  for  the  year=  (3)  +  (4), Ibs. 

6.  Total  pumpage  for  the  year, gallons  |  w^Out  /  allowance 

for  slip. 

7.  Average  static  head  against  which  pumps  work feet. 

8.  Average  dynamic  head  against  which  pumps  work, , feet. 

9.  Number  of  gallons  pumped  per  pound  of  equiva'ent  coal  (5) , 

„         _gallons  pumped  (6)  X8.34(lbs.)  X  rooX dynamic  head(8) 

Total  fuel  consumed  (5) 

Cost  of  pumping,  -figured  on  pumping- station  expenses,  viz.,  $ 

1 1     Per  million  gallons  pumped,  $ 

12.  Per  million  gallons  raised  one  foot  (dynamic),  $ 


ANNUAL  REPORTS. 


FINANCIAL  STATISTICS. 


RECEIPTS. 
Balance  brought  forward: 
(a)  From  ordinary  (mainte- 
nance) receipts              $  

EXPENDITURES. 
Water-works  Maintenance: 
AA.  Operation  (man- 
agement   and 

(6)  From  extraordinary  re- 

repairs) , 

$  

ceipts  (bonds  etc.),         

BB.  Special: 

Total            $ 

From  Water  Rates 

A   Fixture  rates            $ 

CC    Total  maintenance 

$ 

B    Meter  rates               $ 

DD.  Interest  on  bonds, 

C.  Total  from  consumers     $ 

(CC+DD)  

EE    Payment  of  bonds 

D.  For  hydrants,           $.  .  .  . 

FF.   Sinking-fund, 

E.  For  fountains,             .... 
F.  For    street    water- 
ing, 

Water-works  Construction: 

G.  For  pub.  b'ld'ngs,     

GG    Extension  of 

H  For  miscel  uses 

I.    Gen'l  approp'n,        

HH.  Extension  of 

J.  Total  from  munic.  depts.,  
K.  From  tax  levy,                 

II.      Extension  of 
meters 

L.  From  bond  issue,             

1  r          Qr»<irMal  • 

M.  From  other  sources: 

$  

$  

KK.  Total  construction, 

LL.    Unclassified  expenses: 

MM.  Balance: 
(aa)   Ordinary,               $.  . 
(bb)    Extraordinary, 
Total  balance, 

•• 

N.     Total,                               $  

N.      Total, 

$  

Disposition  of  balance, 

O.  Net  cost  of  works  to  date $. 

P.  Bonded  debt  at  date, $. 

Q.  Value  of  sinking-fund  at  date,      .      .      .   $. 
R.  Average  rate  of  interest per  cent. 


3^4 


MAINTENANCE  AND  OPERATION. 


STATISTICS  OF   CONSUMPTION  OF   WATER. 


1.  Estimated  total  population  at  date,  ............ 

2.  Estimated  population  on  lines  ot  pipe, 

3.  Estimated  population  supplied,  ................  .  ..... 

4.  Total  consumption  for  the  year,  .................  gallons. 

5.  Passed  through  meters  ..................  gallons. 

6. 

7. 

8.  Gallons  per  day  to  each  inhabitant,  ............  ..... 

9.  Gallons  per  day  to  each  consumer,  ................. 

10.  Gallons  per  day  to  each  tap,  .  ................ 

11.  Cost  of  supplying  water,  per  million  gallons,  figured  on  total  main- 

tenance (item  CC)  ,  $  ......  ........... 

12.  Total   cost  of  supplying  water,  per  million  gallons,   figured  on  total 
maintenance  +  interest  on  bonds,  $  .......... 


Percentage  ot  consumption  metered, 

Average  daily  consumption,.  ................  gallons. 


STATISTICS     RELATING     TO     DISTRIBUTION     SYSTEM. 


MAINS. 

1 .  Kind  of  pipe,  .     

2.  Sizes,  from inch  to  ...  .inch. 

3.  Extended feet  during  year. 

4.  Discontinued.  .  .feet  during  year. 

5 .  Total  now  in  use, miles. 

6.  Cost  of  repairs  per  mile,    $ 

7.  Number  of  leaks  per  mile, 

8.  Length    of    pipes     less    than    4 

inches  diam., miles. 

9  '  Number  ot  hydrants  added  dur- 
ing year  (public  and  private), 

10.  Number  ot  hydrants  (public  and 
private)  now  in  use, 

n.  Number  of  stop-gates  added 
during  year, 

12.  Number  of  stop-gates  now  in  use, 

13.  Number    of    stop    gates    smaller 

than  4-inch, 

14.  Number  of  blow-offs, 

15.  Range    of    pressure    on    mains 
Ibs. 

to..  ..Ibs. 


SERVICES. 

16.  Kind  of  pipe 

17.  Sizes, 

18.  Extended feet. 

19.  Discontinued feet. 

20.  Total  now  in  use miles 

21.  Number    of    service-taps    added 

during  year 

22.  Number  now  in  use, 

23.  Average  length  of  service,  .  .feet. 

24.  Average  cost  of  service  for  the 

year,  $ 

25.  Number  of  meters  added 

26.  Number  now  in  use, 

27.  Percentage  of  services  metered 


28.  Percentage  of  receipts  from  me- 

tered water  (B-5-C) 

29.  Number  of  motors  and  elevators 

added 


30.  Number  now  in  use, 


PART   III. 
FRANCHISE.    WATER  RATES.     DEPRECIATION. 

ISOLATED  families  obtain  a  wholesome  water-supply  in  suffi- 
cient quantity  for  individual  use  by  exercising  ordinary  caution 
to  prevent  contamination,  and  with  a  sufficient  expenditure  of 
money  they  may  even  possess  the  convenience  of  water  under 
pressure  in  their  houses  and  drainage  facilities  for  removing 
waste  to  a  safe  distance  from  the  premises.  However,  these 
conveniences  for  family  use  are  rather  expensive,  and  unless  the 
proper  skill  is  bestowed  upon  their  design  and  construction  and 
operation  they  may  prove  a  source  of  considerable  annoyance 
and  inconvenience,  to  say  nothing  of  a  menace  to  health. 

Small  communities  depend  upon  individual  exertion  with 
a  considerable  degree  of  safety  and  satisfaction,  because,  as  a 
rule,  the  buildings  are  so  generally  isolated  that  co-operation  in 
matters  of  water-supply  and  drainage  is  rather  more  than  less 
expensive  than  individual  effort. 

Communities  in  which  the  population  is  sufficiently  dense 
to  render  the  hazard  from  fire  collective  and  the  preservation 
of  the  purity  of  the  individual  water-supply  interdependent,  and 
in  which  the  rights  and  interests  are  clearly  interwoven,  find 
economy  and  security  in  co-operation.  The  larger  the  community 
the  more  imperative  becomes  the  necessity  for  united  action 
as  a  municipality.  A  community  desiring  the  advantages  which 
united  action  for  the  common  good  bestows  often  undertakes 
the  development  and  distribution  of  a  public  water-supply  as 
a  purely  municipal  enterprise,  and  with  the  undertaking  accepts 
all  the  attending  responsibilities.  These  responsibilities  increase 
in  the  direct  proportion  in  which  the  increasing  density  of  the  pop- 

385 


386  FRANCHISE.     WATER  RATES.     DEPRECIATION. 

ulation  of  the  community  itself  and  of  the  adjoining  neighbor- 
hood multiplies  the  dangers  of  water-supply  pollution,  and  they 
call  for  a  corresponding  increase  of  vigilance  on  the  part  of 
those  in  authority.  But  in  the  interest  of  the  public  welfare 
municipalities  have  the  right  to  delegate  these  obligations  to 
others,  and  for  various  reasons,  in  the  exercise  of  these  rights 
in  the  past,  the  municipality  has  granted  a  franchise  to  some 
individual  or  public-service  corporation,  usually  for  some  speci- 
fied period  of  years,  to  construct  and  operate  water-works,  with 
authority  to  collect  compensation  from  the  water-consumers  at 
rates  not  exceeding  those  of  a  specified  schedule.  Usually  the 
ordinance  granting  the  franchise  also  embraces  a  contract  for 
furnishing  public  fire  protection  and  for  a  restricted  use  of  the 
water  for  other  public  purposes  at  a  specified  rate  of  compen- 
sation. Thus  the  water  service  becomes  largely  a  commodity 
embracing  not  only  a  tangible  necessity  of  life  but  also  a  par- 
ticular form  of  service  ministering  to  the  comforts  and  conve- 
nience of  the  community. 

The  inviting  prospects  of  gain  in  the  production  and  sale  of 
this  commodity  readily  attracted  private  capital,  and  little  diffi- 
culty was  experienced  in  the  past  in  either  granting  or  disposing 
of  a  water-works  franchise  to  parties  who  were  in  a  position  to 
get  the  funds  required  for  construction.  The  essential  element 
which  gave  stability  to  the  enterprise  in  the  eyes  of  the  investor 
was  the  fact  that  the  franchise  carried  with  it  a  contract  bind- 
ing the  city  to  pay  semi  annually,  usually  during  the  life  of  the 
franchise,  a  specified  amount  for  each  and  every  hydrant  in- 
stalled for  fire  protection.  This  hydrant  rent,  being  a  fixed  income, 
was  readily  set  apart  and  pledged  as  interest  for  money  used 
in  the  construction  of  the  water-works  and  was  secured  by  mort- 
gage on  the  plant  and  franchise.  The  plan  of  the  promoters  was 
frequently  to  make  the  money  thus  available  meet  the  cost  of 
the  original  construction.  Sometimes  it  was  more,  sometimes 
less,  than  was  necessary  for  this  purpose. 

The  operating  company  was  usually  stocked  for  a  consider- 
able amount,  but  the  stock  in  many  cases  represented  compara- 
tively little  or  no  original  cash  investment.  Thus  the  stock 
possessed  altogether  a  speculative  value,  depending  upon  the 


FRANCHISE.     WATER  RATES.     DEPRECIATION.  387 

character  of  management,  the  quality  of  the  water  service,  and 
the  degree  of  prosperity  and  growth  of  the  community  served 
by  the  public-service  corporation.  In  the  more  prosperous  cities 
a  rapidly  increasing  business  may  have  brought  value  to  the 
stock  and  accordingly  may  have  resulted  in  profit  to  the  pro- 
moters. In  the  smaller  cities  and  towns  of  comparatively  slow 
growth  this  plan  of  operation  was  not  so  successful,  for  the 
business,  often  increasing  slowly,  could  scarcely  support  the 
interest  on  the  cost  of  the  original  construction  and  meet  the 
ordinary  expenses  of  operation  and  repairs.  Accordingly,  the 
stock  possessed  little  or  no  initial  value,  but  frequently  came  to 
represent  an  actual  cash  investment  in  proportion  to  the  amount 
of  money  expended  in  the  support  and  maintenance  of  the  prop- 
erty during  the  period  of  insufficient  income  for  these  purposes. 
Sometimes  these  conditions  were  aggravated  in  a  large  measure 
by  an  inferior  quality  of  the  water  or  of  the  service  furnished. 

Reorganization  of  the  public-service  corporation  was  not 
uncommon  during  the  life  of  the  franchise,  and  usually  some 
improvements  and  extensions  followed  in  the  wake  of  the  reor- 
ganization. Finally,  in  the  larger  or  more  prosperous  commu- 
nities, the  service  became  entitled  to  and  received  profitable 
patronage.  But,  as  a  rule,  in  the  smaller  communities,  con- 
siderable portions  of  the  franchise  life  usually  elapsed  before 
water-works  property  became  wholly  self-supporting.  Consider- 
able time,  effort,  and  expense  were  generaUy  required  to  build 
up  a  profitable  patronage,  and  so  soon  as  this  patronage  drew 
upon  the  plant  for  water  service  to  the  limit  of  its  capacity  it 
became  necessary  to  enlarge,  extend,  and  improve  in  order  to 
maintain  the  service  and  to  accommodate  new  business. 

But  important  and  expensive  improvements  are  subject  to 
much  delay  and  postponement  when  the  necessity  for  these 
becomes  apparent  during  the  later  years  of  a  limited  franchise, 
for  the  reason  that  an  investment  which  provides  for  future  as 
well  as  for  present  requirements  is  often  of  doubtful  expediency 
in  view  of  the  uncertainty  arising  in  connection  with  a  renewal 
of  a  franchise  at  the  expiration  of  the  original  franchise.  This 
uncertainty  and  the  natural  wariness  of  capital  to  seek  invest- 
ment under  such  circumstances  financially  cripples  some  public- 


388  FRANCHISE.     WATER  RATES.    DEPRECIATION. 

service  corporation  and  serves  to  delay  improvements  even  though 
a  failure  to  make  them  promptly  results  in  a  deterioration  of 
service  to  a  greater  or  less  degree.  Public-service  corporations 
which  have  pursued  a  policy  of  anticipating  requirements  in 
making  improvements,  regardless  of  franchise  limitations  as  to 
time,  appear  to  have  suffered  no  serious  impairment  of  their 
investment  as  the  result  of  the  venture,  but  rather  to  have  for- 
tified their  position  to  ask  for  an  extension  of  their  franchise 
privileges.  Nevertheless  there  appears  some  good  basis  for  the 
claim  frequently  made  that  the  indirect  effect  of  a  limited  fran- 
chise for  water-works  is  to  create  conditions  which  serve  to  deteri- 
orate the  water  service  and  in  a  measure  the  physical  property 
during  the  later  years  of  its  time  limitation.  A  remedy  for  this 
alleged  defect  has  been  offered  in  the  form  of  an  indefinite  or  un- 
limited franchise  wholly  independent  of  any  contract,  providing  for 
the  fixing  of  the  charges  for  water  in  some  non-partisan  manner 
and  subject  to  termination  through  purchase  by  the  municipality 
at  a  price  for  the  physical  property  fixed  by  mutual  agreement, 
arbitration,  or  condemnation  proceedings,  and  exacting  a  suit- 
able penalty  for  failure  on  the  part  of  the  public-service  corpora- 
tion to  render  good  service  and  to  furnish  wholesome  water  in 
sufficient  quantity — the  central  idea  being  to  secure,  on  the  one 
hand,  acknowledgment  on  the  part  of  the  municipality  of  the 
existence  of  vested  rights  until  the  franchise  shall  have  expired 
through  the  purchase  of  the  property  by  the  city  in  the  manner 
previously  suggested,  and,  on  the  other  hand,  a  binding  obliga- 
tion upon  the  public-service  corporation  to  provide  wholesome 
water  and  good  service. 

The  suggestion  has  also  been  offered  that  in  order  to  attract 
private  capital  it  may  be  necessary  to  show  a  certain  degree 
of  liberality  in  the  application  of  the  purchasing  power  of  the 
municipality  by  limiting  the  application  of  this  power  to  five- 
year  intervals  for  a  period  of  the  first  ten  to  fifteen  years  of  a 
franchise  and  thereafter  limiting  it  only  to  the  interval  of  a  year, 
for  the  reason  that  as  a  rule  the  first  period  of  ten  or  fifteen 
years  is  the  most  trying  and  uncertain  period  for  the  public 
water-service  corporation. 

There  seems  to  be  considerable  justice  at  times  in  the  claim 


FRANCHISE.     WATER  RATES.     DEPRECIATION.  389 

which  is  made  with  regard  to  the  effect  of  the  limited  franchise  in 
postponing  improvements  to  the  property  of  the  public  water- 
service  corporation,  and  there  is  undoubtedly  some  merit  in  the 
suggestion  of  a  few  years'  delay  in  the  exercise  of  the  option  to 
purchase  in  order  to  allow  proper  time  and  compensation  for  the 
expense  usually  required  to  establish  a  water-works  property  on 
a  paying  basis  and  to  recover  the  equivalent  of  the  depreciation 
of  the  property  resulting  from  progressive  deterioration,  and  pos- 
sibly also  from  the  decrease  in  the  market  value  of  the  materials 
of  construction.  Deterioration  of  the  physical  property  is 
unavoidable  and  should  be  represented  by  a  corresponding 
charge  against  the  earnings  of  the  property  and  by  setting  apart 
in  some  manner  a  portion  of  the  income  of  the  business  as 
compensation  for  the  loss. 

But  provision  in  the  income  for  depreciation  resulting  from 
a  fall  in  the  market  prices  of  the  materials  may  be  altogether 
offset  by  enhancement  of  value  at  some  other  period  of  the  life 
of  the  franchise  resulting  from  a  rise  in  market  prices  above 
those  prevailing  at  the  time  of  construction.  This  situation 
might  very  readily  be  met  by  making  legitimate  cost  the  basis 
of  valuation  for  purchase  or  for  rating  that  portion  of  the  in- 
come required  to  take  care  of  the  actual  investment  in  physical 
property  were  it  not  for  the  fact  that  the  principle  of  the  use 
of  the  market  prices  of  material  prevailing  at  the  time  of  pur- 
chase seems  to  be  regarded  in  many  quarters  as  a  fixed  prin- 
ciple in  the  valuation  of  tangible  or  physical  property.  Assuming 
this  principle  to  be  correct  for  the  purchaser,  then  the  option  to 
purchase  at  one-year  intervals  could  be  readily  exercised  in  a 
year  of  low  prevailing  prices,  but  not  so  readily  exercised  in  the 
same  manner  under  an  option  to  purchase  at  five-year  intervals, 
but  as  the  five-year  option  is  intended  to  apply  only  for  two 
or  three  terms  while  the  business  is  being  established,  the  sug- 
gestion is  made  that  in  all  probability  the  period  of  years  so 
covered  is  one  during  which  a  city  would  be  the  least  likely  to 
exercise  the  option  of  purchase  or  desire  to  do  so,  and  that  the 
practical  effect  of  an  indefinite  franchise  in  the  matter  of  option 
to  purchase  would  be  to  exercise  that  option  during  the  period  of 
one-year  intervals.  Were  this  assumption  correct  it  would  follow 


39°  FRANCHISE.     WATER  RATES.     DEPRECIATION. 

that  the  investment  should  be  protected  by  a  sinking-fund  sup- 
ported by  the  water  rents  against  depreciation  of  that  character, 
but  it  is  open  to  the  objection  that  a  large  discrepancy  between 
the  prices  of  material  at  the  time  of  construction  of  a  water-works 
property  and  at  the  time  of  purchase  is  more  imaginary  than 
real,  for  the  reason  that  in  the  ordinary  course  of  events  either 
the  original  construction  or  the  purchase  of  a  water-works  prop- 
erty is  undertaken  at  a  season  of  general  prosperity  when  the 
prices  of  material  are  firm  and  in  all  probability  above  rather 
than  below  the  general  average  of  the  market  prices. 

The  situation  is  just  this:  the  owner  or  seller  of  a  water- 
works property  bases  his  estimate  of  the  value  of  his  physical 
property  at  cost,  and  the  purchaser  of  that  property  bases  his 
estimate  of  value  on  the  cost  of  duplicating  the  physical  prop- 
erty at  the  time  of  purchase  less  depreciation;  therefore  it  fol- 
lows that  the  income  from  the  sale  of  the  commodity  for  which 
the  plant  was  constructed  must  return  the  owner  not  only  the 
interest  up  to  the  time  of  purchase,  but  also  a  sinking-fund  cover- 
ing the  loss  through  depreciation  of  all  kinds  if  his  investment  is 
secure.  In  the  event  of  a  failure  of  the  income  after  deducting 
the  necessary  expenses  of  operation,  repairs  and  interest  to  net  a 
sufficient  amount  to  provide  the  stated  sinking-fund,  the  owner 
naturally  feels  that  the  value  of  the  physical  property  computed 
on  the  basis  of  cost  of  reproduction  less  depreciation  should  be 
increased  at  least  by  an  amount  which  would  equitably  compen- 
sate him  for  his  losses  during  the  preceding  years,  or  that  his 
ownership  be  undisturbed  until  losses  thus  incurred  have  been 
returned  to  him  with  interest  through  the  earnings  of  subsequent 
years. 

On  the  other  hand  a  purchaser  is  quite  likely  to  regard  these 
losses  as  an  incident  of  a  somewhat  speculative  venture  under  a 
contract  which  not  only  fixes  the  rates  which  can  be  charged  for 
water-service,  but  also  allows  the  purchaser  the  option  to  purchase 
at  stated  intervals,  and  accordingly  the  purchaser  is  inclined  to 
ignore  any  obligation  to  make  good  losses  of  the  character 
described. 

The  conditions  and  circumstances  which  develop  these  radically 
different  views  have  also  developed  quite  as  radical  views  with 


FRANCHISE.     WATER  RATES      DEPRECIATION.  391 

regard  to  the  interpretation  of  that  portion  of  the  franchise 
ordinance  which  relates  to  the  valuation  of  a  water-works  prop- 
erty at  the  time  of  purchase — the  owner  maintaining  that  the  busi- 
ness which  he  has  accumulated  and  the  unexpired  portion  of  his 
franchise,  as  well  as  the  physical  property,  are  equally  elements 
of  value  and  should  all  be  valued;  the  purchaser  maintaining  that 
the  franchise  is  simply  a  grant  which  renders  the  physical  prop- 
erty worth  the  cost  of  reproduction  at  the  market  price  of  the 
materials  of  which  it  is  composed,  less  depreciation,  and  therefore 
possesses  an  inherent  value  only,  or  one  which  admits  of  no  iden- 
tity or  valuation  independent  of  the  physical  property. 

It  is  a  fact,  however,  that  the  owner  of  a  water-works  property 
is  subjected  to  more  or  less  pecuniary  loss  while  he  is  accumulat- 
ing a  patronage  and  at  the  same  time  meeting  regularly  the  fixed 
charges  which  are  necessary  to  properly  operate,  support,  and 
maintain  his  investment,  and  therefore  may  be  entitled  to  a 
consideration  of  these  losses  in  the  valuation  of  his  property,  for 
the  reason  that  the  purchaser  in  taking  possession  of  an  estab- 
lished patronage  as  well  as  a  physical  property  becomes  possessor 
of  a  going  concern  with  an  established  income  and  is  thereby  the 
gainer. 

The  purchaser,  however,  while  he  may  concede  the  equity  of 
considering  a  going  value  in  connection  with  value  of  physical 
property,  in  so  far  as  going  value  relates  to  the  expense  of  accumu- 
lating a  patronage  that  is  sufficient  to  operate  the  physical  prop- 
erty and  support  and  maintain  the  actual  investment  therein,  may 
not  so  readily,  concede  the  equity  of  considering  going  value  as 
it  relates  to  the  establishing  of  a  patronage  and  earnings  in  excess 
of  those  required  for  the  above-stated  purposes  or  those  applied 
to  the  support  of  a  fictitious  investment,  particularly  if  the  pur- 
chaser is  the  grantor  of  the  franchise  which  makes  the  conditions 
possible. 

The  franchises  of  the  past  are  not  comprehensive  enough  with 
regard  either  to  the  rules  which  should  govern  in  appraising  a 
water-works  property  or  which  should  govern  in  the  formation 
and  preservation  of  an  equitable  schedule  of  water  rates — in  fact 
this  weakness  may  extend  to  the  statutory  laws  or  even  to  the 
constitution  of  a  State. 


39 2  FRANCHISE.     WATER  RATES.     DEPRECIATION. 

The  rate  of  interest  on  a  water-works  investment  is  a  matter 
which  depends  upon  circumstances  in  general.  The  rate  may  be 
moderate  or  even  low  under  an  unlimited  franchise  if  the  principle 
of  vested  rights  is  generally  acknowledged  and  morally  accepted 
(for  if  morally  accepted  it  can  easily  be  made  legally  accepted) 
and  if  the  water  rates  are  fairly  and  non-partisanly  adjusted  to 
the  amount  and  general  character  of  the  investment  in  physical 
property  and  to  the  necessary  expenses  incurred  in  establishing 
the  business  on  a  paying  basis. 

Of  course  the  option  of  the  municipality  to  purchase  as  ap- 
plied to  one-year  intervals  eliminates  future  earnings  from  con- 
sideration in  the  matter  of  valuation;  and  the  power  to  adjust 
water  rates  periodically,  to  meet  the  requirements  of  each  city  in 
particular  as  occasion  may  require,  eliminates  speculative  value 
from  such  property,  and  reduces  the  water-works  problem  to  one 
of  good  engineering  and  sound  business  management.  It  may  be 
difficult  to  finance  a  project  shorn  of  its  speculative  attractions 
at  the  present  time,  particularly  a  private  water-works  project, 
for  the  shearing  process  having  been  applied  indiscriminately  in 
many  instances  during  or  at  the  expiration  of  limited  water-works 
franchises,  for  which  condition  of  affairs  municipalities  and  public- 
service  corporations  are  about  equally  responsible,  needs  some 
modification  and  the  use  of  a  methodical  and  equitable  basis  of 
valuation  before  mutual  confidence  is  restored. 

Evidently  there  is  room  for  improvement  of  the  conditions 
under  which  public  water-service  corporations  operate — improve- 
ments which  would  be  generally  beneficial  and  should  command 
the  attention  of  the  public  and  of  legislators  in  some  States  at 
least. 


Water  as  furnished  in  the  form  of  a  public  water-supply  is 
regarded  largely  as  a  commodity.  The  products  of  the  farm  and 
industrial  institutions  are  also  commodities,  but  they  are  sold 
by  specific  measurement,  while  water  as  a  commodity  is  sold 
often  without  any  pretense  of  measurement.  Water  is  cleverly 
regarded  as  a  product  of  nature  and  to  that  extent  may  be  properly 
considered  free  to  all.  So  is  air  a  natural  product,  but  were  air 


FRANCHISE.     WATER  RATES.     DEPRECIATION.  393 

to  be  cooled  or  warmed  artificially,  conducted  in  pipes,  and  cir- 
culated in  dwellings  for  the  seasonal  comfort  of  the  inmates  the 
service  thus  rendered  would  possess  a  value  as  a  commodity 
which  should  not  be  wasted  through  carelessness  or  extrava- 
gance, and  so  with  solar  heat — it  is  free  to  all  as  naturally  dis- 
pensed, but  turned  into  energy  artificially  and  disposed  of  as  a 
commodity,  the  service  thus  rendered  would  have  value  in  defi- 
nite proportion  to  the  amount  consumed.  Even  coal,  the  natural 
product  of  solar  heat,  possesses  comparatively  little  value  until 
mined  and  transported  for  use,  when  it  is  sold  as  a  commodity 
by  definite  measurement. 

But  with  water  service  too  little  consideration  is  given  to 
the  expense  of  collecting  and  distributing  it,  and  of  removing 
the  pollution  naturally  or  artificially  present,  to  arouse  unquali- 
fied assent  to  treating  it  thoroughly  as  a  commodity  subject  to 
sale  in  a  definite  amount.  The  sale  of  water  service  without 
measurement  for  a  specified  annual  cost,  regardless  of  the  amount 
of  water  used,  is  manifestly  a  crude  basis  of  dispensing  a  com- 
modity, accommodating  itself  to  a  day  and  an  age  when  a  cheap 
and  convenient  method  of  measurement  was  unknown.  It  is  a 
method  which  appeals  to  the  sense  of  justice  neither  of  the  seller 
nor  the  purchaser,  but  is  nevertheless  strongly  intrenched  behind 
custom. 

The  value  of  a  specific  volume  of  any  commodity  depends, 
first,  upon  the  costs  of  producing  and  distributing  it;  second,  upon 
the  cost  of  maintaining  indefinitely  the  methods  and  means 
through  which  the  production  and  distribution  of  the  commodity 
are  effected.  All  of  these  costs  become  distinctive  elements  of 
value  which  vary  relatively  in  different  localities.  The  greater 
the  distance  water  must  be  conveyed,  the  higher  the  elevation 
to  which  it  must  be  lifted,  and  the  more  labor,  fuel,  and  sup- 
plies that  are  consumed  in  collecting,  purifying,  and  distributing 
water  at  serviceable  pressure,  the  greater  becomes  the  cost  and 
the  value  of  the  water  service.  It  may  require  20  feet  of  pipe- 
line in  one  city  to  carry  water  from  one  consumer  to  the  next 
consumer,  and  100  feet  in  another  city;  but  one  thousand  gal- 
lons of  water  in  one  city  is  one  thousand  gallons  in  another  city, 
and  it  may  cost  five  cents  to  make  that  one  thousand  gallons 


394  FRANCHISE.     WATER  RATES.     DEPRECIATION. 

serviceable  to  a  consumer  in  one  city  and  ten  cents  or  more 
in  another  city.  Therefore  the  water-service  tariff  must  be 
graded  to  suit  different  conditions  and  localities  if  it  is  expected 
to  produce  an  income  which  will  properly  support  the  invest- 
ment in  water-works  property  in  all  cases.  A  deficit  in  this 
particular  may  affect  a  public -service  corporation  more  directly 
than  it  affects  a  municipality,  because  of  the  latter's  ability  to 
make  up  any  deficit  of  water-service  revenue  through  a  tax  levied 
upon  the  property  of  the  citizens.  But  even  the  taxing  power 
of  a  city  is  limited  by  law,  and  if  a  deficit  in  water-service  income 
continues  and  finally  becomes  too  great  annually  to  be  made 
up  through  special  taxation,  a  floating  debt  accumulates  which 
may  become  a  serious  matter,  whether  the  municipality  can  or 
cannot  absorb  it  legally  through  an  issue  of  bonds.  A  situation 
of  this  kind  is  likely  to  confront  a  city  engaged  in  the  manage- 
ment of  public  utilities,  particularly  if  expenditures  in  construc- 
tion are  heavy:  either  the  water  tariff  to  the  consumer  must 
be  proportionately  heavy  or  the  tax  upon  the  property  more 
or  less  burdensome.  Under  such  circumstances  the  city  cannot 
permit  water  to  be  wasted  and  should  sell  above  the  cost  of  produc- 
tion in  cases  where  the  property  is  taxed  for  interest  and  sink- 
ing-fund of  bonds  issued  for  construction  purposes.  The  only 
safe  course  for  small  cities  in  general  and  those  in  particular 
heavily  indebted  for  water-works  is  to  sell  water  service  by 
measurement  and  above  cost,  yet  not  at  a  price  which  is  pro- 
hibitive. For  a  year  or  two  in  the  beginning  of  the  public  water 
service,  while  connections  are  being  made  for  consumers,  a  deficit 
of  revenue  may  result,  which  may  have  to  be  provided  for  either 
through  a  special  tax  or  out  of  the  general  fund  until  made  up 
out  of  the  surplus  revenue  of  succeeding  years. 

It  is  difficult  indeed  to  present  figures  convincingly  to  a  com- 
munity on  the  eve  of  embarking  upon  a  water-works  manage- 
ment and  to  impress  upon  it  the  importance  of  adopting  a  water 
rate  fitted  to  its  local  requirements  or  of  insisting  at  the  out- 
start  on  adopting  methods  of  management  which  will  insure  good 
plumbing  and  freedom  from  waste  and  extravagant  use  of  water. 
As  a  rule,  the  community  regarding  water  service  cheaply  adopts 
the  annual  rate  sheet  of  some  neighboring  town,  possibly  reduc- 


FRANCHISE.      WATER  RATES      DEPRECIATION.  395 

ing  the  rates  somewhat,  regardless  of  its  adaptation  to  the  local 
situation  and  requirements.  The  fact  that  the  water-works  do 
not  pay,  but  annually  accumulate  a  deficit,  is  something  of  a 
revelation  and  becomes  the  source  of  more  or  less  political  bicker- 
ing. It  may  require  several  years  of  experience  to  locate  the 
source  of  trouble  and  still  longer  to  correct  it,  for  the  difficulty 
politically  of  raising  a  schedule  of  water  rates  is  great  even  though 
the  necessity  for  doing  so  is  apparent  to  every  one. 

The  error  committed  is  a  double  one:  first,  in  ever  consider- 
ing for  a  moment  any  other  method  of  selling  the  water  than 
by  actual  measurement;  second,  in  not  having  made  the  rate 
high  enough  to  cover  the  cost  of  producing  the  water  service, 
after  allowing  one  to  three  years  for  acquiring  patronage,  or  in 
not  making  it  even  higher,  for  if  made  too  high  it  can  be  gradu- 
ally reduced  without  difficulty  after  making  up  the  first  year 
or  two  of  loss. 

However,  there  is  a  form  of  water  service  which  must  be  con- 
sidered, but  to  which  the  observations  of  the  few  preceding  pages 
relating  to  the  water  service  for  domestic  and  trade  purposes 
must  be  applied  with  considerable  modification.  Probably  the 
annual  rate  for  the  use  of  an  indefinite  amount  of  water  is  the 
most  practical  and  convenient  method  of  charging  for  water 
consumed  in  fire-service,  excepting  so  far  as  the  fire-hydrants 
may  be  used  for  other  purposes  than  the  extinguishment  of  fires, 
when  the  actual  volume  so  abstracted  from  a  hydrant  should 
become  the  basis  of  sale  and  purchase.  This  modification  becomes 
necessary  largely  because  there  is  no  simple  and  satisfactory 
way  of  measuring  the  large  volume  of  water  used  for  fire  pur- 
poses. The  danger  of  waste  of  water  in  fire-service  is  small,  for 
ordinarily  the  penalties  imposed  by  city  ordinance  for  the  unau- 
thorized use  of  fire-hydrants  are  sufficiently  rigid  to  prevent 
waste  of  water,  in  view  of  the  fact  that  the  hydrants  are  upon 
public  ground  and  continually  exposed  to  public  gaze  and  police 
surveillance.  Moreover,  the  water  actually  used  for  fire-service 
annually  is  small  in  the  aggregate,  but  large  relatively  for  the 
brief  periods  that  it  is  required  for  use. 

The  essential  principle  of  good  fire  protection  is  a  prompt 
and  capacious  service  which  can  be  applied  in  large  volume  imme- 


396  FRANCHISE.     WATER  RATES.     DEPRECIATION. 

diately  upon  the  discovery  of  a  fire  and  before  it  can  have  time 
to  spread  to  uncontrollable  proportions.  The  application  of  this 
principle  requires,  first,  an  abundance  of  water  and  a  capacity 
of  plant  in  excess  of  that  required  for  the  ordinary  daily  con- 
sumption; second,  a  continuity  of  service  that  can  respond  effi- 
ciently to  fire  requirements  upon  demand.  In  the  densely  occu- 
pied districts  of  the  business  centers  of  large  cities,  where  there 
may  be  many  large  and  lofty  buildings,  the  demand  for  ade- 
quate fire  protection  is  so  excessive  as  often  to  require  a  sys- 
tem of  street  pipes  and  pumping  machinery  entirely  independent 
of  the  system  used  for  the  distribution  of  water  for  general  pur- 
poses. This  kind  of  protection  any  city  possessing  building  dis- 
tricts of  the  kind  described,  particularly  if  occupying  a  site  of 
rugged  topography,  can  well  afford  to  provide,  and  the  city  should 
impose  a  direct  tax  upon  the  property  immediately  benefited, 
covering  the  cost  of  operation  and  possibly  of  maintenance  of 
the  district  fire  protection,  thus  freeing  the  city  as  a  whole  from 
all  obligation  except  that  of  providing  the  means  for  making 
the  original  investment  in  physical  property  for  this  specific 
purpose. 

The  expense  of  fire-service  for  which  property,  generally 
speaking,  is  liable  is  at  least  twofold:  one  the  expense  of  sup- 
porting and  maintaining  the  investment  in  the  physical  property 
in  excess  of  that  required  for  the  ordinary  water-service  con- 
sumption; the  other  the  expense  of  the  annual  outlay  required 
in  support  of  an  ever-ready  and  prompt  fire-service.  It  is  clearly 
the  part  of  the  property  to  bear  this  expense. 

The  public-service  corporation  in  its  dealings  with  the  munici- 
pality has  attempted  to  meet  the  situation  by  charging  the 
city  some  specific  amount  annually  for  each  hydrant  as  hydrant 
rent  and  obligating  the  city  to  provide  the  hydrant  rents  by 
annually  levying  a  tax  for  the  purpose  upon  property.  The 
governing  principle  underlying  the  annual  charge  for  fire-ser- 
vice, termed  hydrant  rent,  was  intended  in  many  cases  to  pro- 
duce a  distinct  fund  of  an  amount  which  in  the  aggregate  would 
be  sufficient  to  pay  the  interest  on  the  cost  of  the  original  water- 
works. The  application  of  the  principle  of  property  participation 
in  water-works  maintenance  in  the  manner  described,  though  it  does 


FRANCHISE.     WATER  RATES.     DEPRECIATION.  397 

not  discriminate  between  an  investment  made  for  fire  protection 
only  and  that. made  for  ordinary  industrial  and  domestic  purposes, 
is  in  effect  but  little  different  from  the  case  when  a  municipality 
building  its  own  water-works  taxes  the  property  for  the  interest 
on  the  bonds  issued  for  the  purpose  of  general  construction  and 
for  the  support  of  a  sinking-fund  to  redeem  the  bonds  at  maturity. 
The  difference  in  the  two  applications  of  the  same  principle  is 
solely  the  difference  of  the  rate  of  interest  paid  on  private  and 
city  bonds  respectively,  in  view  of  the  fact  that  the  obligation 
to  support  a  sinking-fund  should  rest  equally  upon  both  parties. 
Neither  application  of  the  principle  may  be  strictly  equitable 
as  between  the  obligations  of  the  property  and  the  consumer 
in  the  support  of  a  water  service;  still,  in  spite  of  its  shortcoming, 
it  may  have  been  and  may  yet  be  under  existing  conditions  an 
easy  practical  way  of  solving  a  problem  otherwise  intricate  and 
uncertain,  at  least  for  the  five  or  ten  years  following  the  first 
construction  of  a  water- works.  After  a  period  of  years,  which 
may  vary  in  length  in  different  localities,  the  principle  may  be 
applied  upon  a  more  equitable  basis;  that  is  to  say,  it  may  be 
based  upon  an  equitable  division  of  the  investment  as  between 
the  requirements  for  fire-service  and  those  for  domestic  and 
industrial  purposes. 

But  in  view  of  the  fact  that  hydrant  rent  has  developed  into 
a  stumbling-block  for  both  the  public-service  corporation  and  the 
municipality,  it  seems  as  though  further  discrimination  should 
be  made  in  proportion  to  the  benefits  received  and  to  the  fire 
hazard  to  which  property  is  exposed  in  different  districts  of  a 
city.  It  is  known  that  a  densely  built-up  portion  of  a  city  is 
more  exposed  to  a  fire  hazard  than  is  the  residential  portion, 
and  that  this  hazard  further  decreases  in  proportion  to  the  degree 
of  isolation  of  independent  residences.  In  a  city  of  rugged  topog- 
raphy, buildings  on  low  ground  receive  better  fire-service  than 
those  on  high  ground,  and  buildings  near  are  better  served  than 
buildings  remote  from  the  center  of  water  distribution.  The 
mechanical  facilities  for  stopping  a  fire  are  more  accessible  and 
more  promptly  concentrated  in  the  business  portion  than  in  the 
residential  portion  of  a  city,  a  situation  which  affects  only  indi- 
rectly the  available  service  of  the  pipe  system.  Moreover,  the 


398  FRANCHISE.     WATER  RATES.     DEPRECIATION. 

pipe  capacity,  often  carried  through  low-lying  and  near-by  dis- 
tricts in  order  to  reach  high  level  and  remote  districts,  affords 
the  low-level  districts  a  direct  benefit  which  is  not  available  to 
less  favorably  located  districts.  It  would  seem,  therefore,  that 
hydrant  rent  should  be  graduated  by  a  sliding  scale  in  pro- 
portion to  the  efficiency  of  the  available  service,  depending  upon 
location  geographically  and  topographically  with  respect  to  the 
densely  built-up  populated  district  and  the  center  of  water  dis- 
tribution. The  argument  may  be  advanced  that  all  districts 
of  the  city  should  be  treated  alike  in  this  regard  and  a  flat-rate 
hydrant  rent  prevail,  for  the  reason  that  a  wide-spread  calamity 
in  a  business  district  extends  its  effect  throughout  the  city  regard- 
less of  boundaries  artificially  established,  and  that  consequently 
all  are  equally  benefited  morally  and  socially  in  the  facilities 
and  preparation  for  avoiding  such  a  calamity.  But  the  argu- 
ment cannot  apply  to  a  property-holder  in  both  the  business 
and  residential  districts,  for  his  pecuniary  liability  is  balanced 
in  the  application  of  a  sliding-scale  system  of  fire-protection 
charges,  and  should  not  apply  to  the  wage-earner  depending 
upon  the  progress  and  integrity  of  the  business  district,  for  gen- 
erally he  is  not  a  direct  participant  in  the  profits  of  the  busi- 
ness or  in  the  rents  of  real  estate. 

A  sliding  scale  of  hydrant  rentals  should  embrace  scarcely 
more  than  three  or  four  classifications  of  hydrants,  but  of  an 
amount  which  should  be  fixed  for  each  town  independently, 
depending  upon  the  natural  conditions  affecting  the  distribution 
of  water  and  the  rendering  of  a  proper  fire-service. 

The  custom  ordinarily  followed  in  the  past  of  introducing 
in  a  franchise  ordinance  the  height  of  some  stated  number  of 
hose-streams  delivered  through  specified  length  of  hose  and 
size  of  nozzles  to  some  stated  height,  as  a  basis  of  measuring  the 
efficiency  of  a  proper  fire-service,  is  rather  a  crude  method  of 
measurement  and  subject  to  a  conflicting  interpretation  of  results. 
Its  only  merit  is  its  impressiveness  in  facilitating  opinions  which 
may  be  either  favorable  or  unfavorable,  depending  upon  the 
visible  result,  regardless  of  the  effect  of  the  hose  between  the  hy- 
drant and  the  nozzle  upon  the  height  and  efficiency  of  the  stream 
issuing  from  the  nozzle. 


FRANCHISE.     WATER  RATES      DEPRECIATION. 


399 


The  resistance  of  fire-hose  to  the  flow  of  water,  though  it  is 
a  matter  usually  well  understood  and  appreciated  by  a  public- 
service  corporation,  is  often  misunderstood  or  disregarded  by 
the  casual  observer  and  even  by  members  of  a  fire  department. 
Controversies  over  fire-stream  efficiency  on  particular  occasions 
have  arisen,  and  the  most  frivolous  sort  of  evidence  has  been 
introduced  in  court  in  support  of  a  claim  of  inefficiency  of  fire- 
service,  which  a  resort  to  the  development  of  the  facts  and  cir- 
cumstances could  have  avoided. 

'.  he  painstaking  and  elaborate  experiments  of  John  R.  Free- 
man have  given  us  a  reliable  standard  with  which  the  efficiency 
and  capacity  of  fire-hose  may  be  very  satisfactorily  compared  and 
deficiencies  observed.  Commercial  considerations,  often  control- 
ling the  selection  of  an  equipment  of  a  fire  department,  may 
result  in  an  inefficiency  of  fire-service  for  which  the  system  of 
street  pipes  and  its  equipment  is  in  nowise  responsible.  Obser- 
vations recently  made  of  fire-department  hose  gave  the  results 
expressed  in  the  following  table: 

TABLE  I. 


Equipment. 

Pressure  measurements. 

Friction  loss  from 
Freeman's  tables. 

Length 
of  hose 
in  feet. 

Size 
of  nozzle 
in  inches. 

Nozzle 
in  pounds. 

Hydrant 
in  pounds. 

Actual 
resistance 
per  loo  feet 
in  pounds. 

Inferior 
rubber-lined 
cotton-mill 
hose,  inside 
rough. 

Ordinary 
best  quality 
rubber-lined 
hose,  inside 
smooth. 

100 

S* 

IOO 

124 

24 

44 

25 

100 

s. 

82 

107 

25 

37 

22 

100 

S. 

66 

87 

21 

30 

16 

IOO 

s. 

62 

85 

23 

28 

15 

100 

s. 

60 

80 

2O 

27 

15 

IOO 

s. 

45 

60 

15 

20 

II 

500 

s. 

34 

91 

zz.  4 

13-6 

7 

*  i"  smooth  nozzle. 

The  tests,  with  the  exception  of  the  first  one  recorded,  show  a 
deterioration  of  hose  or  predominating  tendency  to  a  selection 
of  rather  an  inferior  quality  of  hose,  although  in  the  assortment 
there  were  some  sections  of  a  very  good  quality.  The  first  test 
under  100  pounds  pressure  indicates  a  friction  loss  of  a  less  amount 
than  that  indicated  bv  Freeman's  tables,  a  circumstance  which 


400 


FRANCHISE.     WATER   RATES.     DEPRECIATION. 


was  probably  due  to  the  expansion  of  the  hose  while  under  the 
stated  high  working  pressure. 

To  illustrate  the  effect  of  the  variation  of  the  diameter  of 
hose  from  the  nominal  diameter  of  2i  inches  the  following  com- 
putation is  made  under  the  recognized  physical  law  that  the 
discharge  varies  as  the  square  foot  of  the  fifth  power  of  the  diam- 
eter, and  the  resistance  inversely  as  the  fifth  power  of  the  diam- 
eter, hence  the  following  tabulation: 

TABLE  II. 


Diameter  of  hose 

Ratio  of 

Ratio  of 

in  inches. 

resistance. 

discharge. 

2| 

I  .29 

0.88 

2T^ 

1  •  T3 

0.94 

2i 

I  .00 

I  .00 

2  A 

0.88 

i  .06 

2f 

0.78 

i-i3 

The  table  shows  that  for  a  decrease  of  hose  diameter  of  TV  of 
an  inch  the  resistance  is  increased  13  per  cent  or  more,  and  the 
discharge  decreases  6  per  cent,  and  for  an  increase  of  hose  diam- 
eter by  a  like  amount  the  resistance  is  decreased  12  per  cent, 
and  the  discharge  increased  6  per  cent. 

The  illustration  develops  good  reasons  for  desiring  a  better 
basis  of  determining  the  efficiency  of  fire-service  relating  to  the 
street  pipes  than  a  physical  test  of  fire  streams.  The  fact  that 
Freeman's  tables  are  accepted  as  a  standard  affords  opportunity 
of  basing  measurements  of  fire-service  efficiency  of  the  pipe  sys- 
tem upon  pressure  observations  at  the  hydrant,  leaving  the  respon- 
sibility for  the  use  of  inferior  grades  of  hose  upon  the  party  respon- 
sible for  its  selection,  where  it  belongs. 

The  progressive  introduction  of  meters  is  gradually  placing 
water-works  upon  a  more  rational  basis  of  dispensing  water  ser- 
vice as  a  commodity.  But  notwithstanding  the  fact  of  progress 
in  this  direction  there  is  still  a  well-marked  popular  objection 
to  the  use  of  meters,  which  only  time  and  acquaintance  with  this 
system  of  measurement  can  overcome.  However,  in  view  of 
the  past  prevalence  of  the  annual  rate  system,  it  is  interesting 
to  see  its  effect  upon  revenue  and  the  financial  support  which 
it  has  afforded  water-works  property. 


FRANCHISE.     WATER  RATES.     DEPRECIATION. 


401 


The  Fourteenth  Annual  Report  of  the  Commissioner  of  Labor 
for  1899  gives  information  from  which  the  following  data  have 
been  compiled.  In  the  computations  no  distinction  is  made 
between  revenue  earned  by  meter  and  that  earned  by  the  appli- 
cation of  the  annual  rate  system,  but  generally  the  annual  rate 
predominates.  A  showing  is  made  of  gross  income  independent 
of  the  hydrant  rent  or  the  income  from  the  sale  of  water  used 
for  public  purposes,  in  order  that  the  income  of  private  water- 
works may  be  compared  with  the  income  from  municipal  water- 
works. This  comparison  may  not  be  altogether  a  fair  one,  for 
the  reason  that  the  extent  to  which  the  taxing  power  of  munici- 
palities may  have  been  used  to  make  up  a  deficit  of  income  from 
water  rate  is  unknown. 

TABLE  III. — PRIVATE  WATER-WORKS. 


Average  annual  income  and  cost  per  million  gallons. 

Average  annual 
consumption  in 
million  gallons. 

Gross  income. 

Total  cost 

Gross  income, 

Interest 

Gross  income. 

less  hydrant 

of  production 

less  cost  of 

on 

rent. 

and  taxes. 

production. 

investment. 

i    to            5 

$447.60 

$275-5° 

$195.28 

$252.32 

$2  .90 

5                       I0 

347.60 

226.  II 

I59-58 

188.02 

3-5° 

10                      15 

252  .  10 

167.24 

162.74 

89.36 

2.80 

15                      20 

237.20 

I4L35 

118.16 

119.04 

5.06 

20                           25 

216.40 

169.05 

106.94 

109.46 

5-42 

25                  5° 

152.40 

112  .  50 

65-37 

87.03 

5-24 

50                  75 

128.11 

98.48 

50-43 

77.68 

6-65 

75                ioo 

118.30 

87.04 

60.02 

58.28 

4.71 

100                125 

97-30 

66.91 

43-0° 

54-30 

6.04 

125                150 

105.90 

78.39 

47-79 

58.11 

5.26 

150                175 

90.  20 

63.80 

45-84 

44.36 

5.63 

175                        200 

98.  10 

67.71 

55-5i 

42.59 

4-85 

2OO                        250 

96.30 

73.28 

41.98 

54.32 

6-33 

250                        500 

70.50 

55-22 

29.40 

41  .  10 

6.36 

500                       750 

58.90 

44.30 

26.93 

31.97 

5  -06 

750              1000 

61.80 

48.50 

26.33 

35-47 

5-55 

1000              5000 

56-3o 

46.42 

21.93 

34-37 

5-53 

5000             10000 

113.60 

100.74 

39-93 

73-67 

7.10 

Examination  of  Tables  III  and  IV  shows  clearly  that,  notwith- 
standing the  comparatively  large  gross  income  received  and  the 
reasonable  cost  of  production  annually  per  one  million  gallons 
by  private  water  companies,  the  net  income  averages  only  a 
small  rate  of  interest  on  the  investment,  if  provision  be  made 
for  a  sinking-fund.  The  reason  of  this  in  small  communities 


402 


FRANCHISE.     WATER  RATES.    DEPRECIATION. 


is  due  in  a  great  measure -to  the  fact  that  the  cost  of  the  pipe 
system,  comprising  the  greater  portion  of  the  expense  of  the 
water- works  plant,  is  relatively  far  greater  than  the  large  pipe 
system  of  a  large  town  when  compared  upon  a  basis  of  capacity. 
For  instance,  a  48-inch  pipe  line  will  cost  about  four  times  as 
much  as  a  12-inch  pipe  line,  and  the  latter  about  three  times  as 
much  as  a  4-inch  pipe  line;  but  the  capacity  to  furnish  water 
at  an  equal  velocity  of  the  48-inch  pipe  is  sixteen  times  that 
of  the  12-inch  pipe,  and  the  latter  nine  times  that  of  the  4-inch 
pipe,  while  the  capacity  for  an  equal  friction  loss  per  unit  of 
length  is,  similarly,  for  the  48-inch  thirty-three  times  the  12-inch, 
and  the  latter  nearly  eighteen  times  the  4-inch  pipe  capacity. 
Accordingly,  small  communities  are  frequently  more  heavily 
taxed  per  unit  of  pipe  capacity  for  the  construction  and  main- 
tenance of  water-works  than  are  large  communities. 

TABLE  IV. 


Municipal  plants. 

Private  plants. 

Average  annual 
in  million 

consumption 
gallons. 

Average  annual  income  and  cost  per  million  gallons. 

Gross  income. 

Cost  of  production. 

Cost  of  production, 
less  taxes. 

I       tO 

5 

$203  .  IO 

$298.80 

$146.40 

5 

10 

I57-90 

I50-30 

I53-5° 

10 

15 

144.50 

115.80 

138.20 

15 

20 

109.00 

101  .80 

96.  20 

20 

25 

110.80 

84.80 

102  .00 

25 

5° 

84.00 

60.60 

58-50 

5° 

75 

74.30 

42.30 

43-40 

75 

IOO 

79.20 

46  .  10 

51  .  10 

IOO 

125 

63.90 

34-20 

36.80 

125 

15° 

64.00 

38.10 

37-70 

150 

175 

58.00 

16.40 

40.  80 

175 

200 

69.30 

25.40 

47.00 

2OO 

250 

88.90 

26  .  90 

36.30 

25O 

5OO 

61  .  50 

22  .  70 

25  .  10 

5OO 

75<> 

70.80 

25.20 

20.60 

75° 

IOOO 

6  1  .00 

19.50 

19.40 

IOOO 

5000 

59-30 

I7-50 

17  .60 

5000 

IOOOO 

47.10 

10.  70 

29.  10 

Over  10000 

52.60 

16.  70 

The  following  interesting  comparisons  may  be  made  of  the 
preceding  tables,  omitting  consideration  of  the  first  three  groups 


FRANCHISE.     WATER  RATES.     DEPRECIATION.  403 

embracing  annual  consumption  of  water  from  i  to   15  million 
gallons: 

Average  total  gross  earnings  of  private  plants,  per  million  gallons.  .$i  13  .42 

Per  cent  of  total 
gross  earnings. 

Average  gross  income  private  plant,  less  hydrant  rent 73-7 

Average  gross  income  private  plant,  less  cost  of  production 54-2 

Average  cost  of  production  and  taxes   45.8 

Average  cost  of  production,  less  taxes 38.9 

Average  gross  income  of  municipal  plant 63  . 6 

Average  cost  of  production  of  municipal  plant 32.5 

Average  rate  of  interest  which  gross  earnings,  less  taxes  and  cost 

of  production,  will  pay  on  private  investment  is  shown  to  be.  .  5 . 65% 

Deductions  made  from  the  foregoing  table  show  the  excess 
income  of  the  private  water-works  over  municipal  water-works, 
amounting  to  $41.28,  to  be  distributed  as  follows  per  one  million 
gallons: 

Average  hydrant  rents $29 . 83 

Average  taxes 7-83 

Income  from  commercial  sources 3-62 

$41.28 

That  portion  of  the  total  gross  income  which  remains  after 
deducting  the  cost  of  production  and  taxes  is  seen  to  pay  an 
average  of  5.65  per  cent  on  the  average  investment.  Many  of 
the  public-service  corporations  mortgaged  the  water-works  prop- 
erty to  raise  the  funds  for  construction,  and,  from  sources  of  infor- 
mation independent  of  the  report  referred  to,  it  is  found  that 
out  of  a  total  of  358  private  water-works  in  27  different  States 
scattered  throughout  the  Union  61.2  per  cent  floated  securities 
at  6  per  cent,  and  that  the  average  rate  of  interest  of  all  the 
securities  is  5.82  per  cent. 

It  is  also  noticed  that  the  cost  of  production  of  the  municipal 
plants  is  $7.26  per  million  gallons  less  than  the  corresponding 
cost,  exclusive  of  hydrant  rent  and  taxes,  of  private  plants — a 
difference  due  largely  to  the  greater  amounts  expended  in  salaries 
under  private  management.  The  discrepancy  is  not  material 
except  in  relation  to  the  larger  plants,  where  it  is  quite  as  likely 
to  be  due  to  conservatism  on  the  one  hand  as  to  liberality 
on  the  other.  The  discrepancies  in  three  groups  of  plants 


404  FRANCHISE.     WATER  RATES.     DEPRECIATION. 

would  indicate  such  a  probability  and  that  an  average  might 
consistently  be  taken  of  the  cost  of  production  of  those  groups 
of  plants  where  the  difference  is  material.  The  predominating 
character  of  the  system  of  water-works,  whether  gravity  or 
pumping  system,  would  necessarily  influence  the  average  in  the 
respective  cases. 

Were  the  discrepancy  to  be  averaged  it  would  make  the  aver- 
age rate  of  interest  on  the  average  investment  scarcely  6  per 
cent.  It  is  apparent,  therefore,  that  the  statistics  show  in  a 
general  way  little  or  no  speculative  value  in  private  water-works 
property  as  a  class,  also  that  the  average  income  has  been  insuffi- 
cient to  provide  a  sinking-fund  to  cover  depreciation  resulting 
from  the  progressive  deterioration  of  the  physical  property  dur- 
ing the  usual  life  of  a  limited  franchise. 

This  condition  of  income  of  water-works  operated  under  a 
limited  franchise  must  sooner  or  later  react  disastrously  and 
represents  a  substantial  foundation  for  the  claim  now  frequently 
heard  of  the  importance  of  the  unlimited  franchise  as  applied 
to  the  successful  operation  and  maintenance  of  this  particular 
form  of  public-service  property.  It  is  also  clear  that  a  4  or  5  per 
cent  investment  under  an  unlimited  franchise  giving  good  ser- 
vice would  be  worth  more  to  an  investor  and  would  prove  more 
satisfactory  to  the  consumers  than  a  6  per  cent  investment  under 
a  twenty-year  franchise  with  every  incentive  offered  at  times 
to  squeeze  the  service  in  order  to  protect  the  investor  from  loss 
through  unavoidable  depreciation  and  the  uncertainty  of  the 
future  when  the  franchise  shall  have  expired. 

It  is  quite  certain  that  the  influence  of  metered  services  instead 
of  the  predominating  influence  of  the  annual  rate  system  during 
the  past  experience  of  water-works  public- service  corporations 
would  have  acted  as  a  protection  to  the  water-service  patrons 
and  the  investor  jointly  by  eliminating  an  incentive  to  economize 
unduly  and  eliminating  also  the  losses  attending  the  waste  of 
water  and  service  which  has  prevailed  to  a  greater  or  less  extent 
under  the  influence  of  the  annual  rate  system. 

So  long  as  water  service  is  considered  a  commodity  the  income 
from  the  sale  of  it  under  private  management  should  pay  the 
interest  on  the  investment  in  physical  property  actually  required 


FRANCHISE.     WATER  RATES.     DEPRECIATION.  405 

to  produce  the  commodity,  a  sinking-fund  to  redeem  the  invest- 
ment eventually  and  to  renew  the  physical  property  as  it  becomes 
useless,  operating  expenses,  minor  repairs,  taxes,  insurance,  and 
in  addition  a  reasonable  surplus  to  meet  emergencies.  The  longer 
and  more  secure  the  iranchise  under  which  a  private  property 
is  built  and  operated  the  lower  should  be  the  rate  of  interest 
and  sinking-fund. 

A  municipality  operating  its  own  water-works  as  though 
producing  a  commodity  must  necessarily  follow  a  similar  course, 
except  that  the  interest  and  sinking-fund  in  part  may  be,  as  they 
usually  are,  a  tax  upon  the  property,  and  the  income  from  the 
consumers  may  be  limited  to  the  actual  cost  of  production  plus 
a  part  of  the  sinking-fund  and  an  excess  to  cover  emergency 
expenses  and  repairs.  But  a  city  is  privileged  to  cease  treating 
the  water  service  as  a  commodity,  or  to  deliver  the  water  at 
cost  or  below,  and  to  provide  for  a  deficit  in  any  amount  by  appor- 
tionment from  the  general  fund  of  the  city,  or  by  a  special  or 
general  tax  upon  the  property  of  the  city,  or  any  combination 
of  these  facilities  that  may  be  convenient  and  legal.  The  de- 
parture from  the  commodity  basis  is  not  liable  to  result  in  any 
economy  or  improvement  of  the  water  service  to  the  consumer 
or  the  public  generally,  and  is  rather  a  dangerous  expedient  for 
small  towns  to  adopt,  as  pointed  out  on  preceding  pages.  The 
method  will  prove  a  fitting  companion  to  the  annual  rate  basis 
of  dispensing  a  water  service,  for  the  reason  that  it  places  no 
check  upon  extravagance  or  waste,  and  presents  no  lesson  in  the 
matter  of  either  personal  or  civic  economy.  Moreover  the  burden 
of  the  expense  attending  either  the  reckless  or  extravagant  use  of 
the  water  service  falls,  as  a  rule,  most  heavily  upon  the  provident 
rather  than  the  improvident,  upon  the  careful  rather  than  the 
careless  or  extravagant  citizens. 

Among  the  objections  to  the  general  use  of  a  water-meter, 
the  prejudice  or  misunderstanding  of  the  general  public  is  more 
easily  overcome  than  is  the  objection  of  the  owners  of  rental 
property  who  desire  to  avoid  responsibility  for  the  careless  use 
of  fixtures  by  tenants.  Experience  will  usually  overcome  preju- 
dice in  this  regard,  but  some  method  may  be  necessary  to  com- 
pel the  owner  of  rental  property  to  make  repairs  which  he  per- 


406  FRANCHISE.     WATER  RATES.     DEPRECIATION, 

sistently  neglects  or  will  not  make  voluntarily.  It  is  clear  as  a 
matter  of  self-protection  that  the  tenant  will  insist  upon  freedom 
from  waste  through  leaky  fixtures,  but  has  no  power  to  compel 
the  owner  to  remedy  the  defect.  The  right  to  shut  off  the  water 
should  be  exercised  with  discretion  in  such  a  case  and  need 
not  be  exercised  at  all  if  the  owner,  after  due  notice,  fails  to  make 
the  repairs,  provided  the  value  of  the  water  service  so  wasted 
can  be  charged  against  the  property  and  legally  become  a  first 
lien  against  it.  A  law  or  ordinance  of  this  character  or  a  simi- 
lar one  would  prove  effective. 

The  method  of  dispensing  a  water  service  by  definite  volume 
must  finally  prevail,  and  with  a  view  of  facilitating  the  compu- 
tation of  a  gross  income  a  table  is  prepared,  based  upon  a  general 
average  but  somewhat  modified  cost  of  producing  the  water  service 
contained  in  Table  IV.  The  computation  also  embraces  sepa- 
rately the  elements  of  interest  and  sinking-fund  when  this  support 
is  to  be  provided. 

The  computations  are  intended  simply  as  a  guide  to  the 
judgment,  and  the  cost  of  production  is  regarded  simply  as  a 
base  rate  subject  to  modification  in  particular  cases,  as  indicated 
in  the  memoranda  immediately  following  the  table,  in  instances 
where  more  definite  data  are  not  available. 

The  cost  of  production  is  supposed  to  embrace  all  of  the 
charges,  such  as  salaries  of  administration  and  operation,  wages, 
insurance,  fuel,  supplies,  and  other  minor  items  of  cost. 

The  average  working  pressure  of  the  works  embraced  in  the 
computations  of  Table  V  is  60  pounds,  and  fully  85  per  cent 
of  the  works  have  pumping  machinery. 

The  average  salaries  of  administration  and  operation  are  2 1  per 
cent,  and  average  wages  26  per  cent  of  the  total  cost  of  produc- 
tion, between  the  limits  of  100  and  1000  million  gallons  annual 
consumption. 

Taxes  should  be  added  to  the  cost  of  production  given  in 
Table  V  whenever  they  become  an  element  of  the  annual  expense 
of  operation. 

It  does  not  follow  from  an  inspection  of  the  table  that  a  flat 
meter  rate  is  suggested,  but  that  in  each  particular  case,  after 
the  cost  of  production  shall  have  been  modified  to  suit  the  locality 


FRANCHISE.     WATER   RATES.     DEPRECIATION. 


407 


and  after  such  additions  to  cover  interest  and  depreciation  of 
value  of  the  physical  property  shall  have  been  made,  the  final 

TABLE  V. — BASE  RATE  PER  MILLION  GALLONS. 


A  verage 

Cost  of  production  plus  interest  on  average 

Average  annual 
consumption  in 
million  gallons. 

investment 
per  million 
gallons 
annual  con- 

Average 
cost  of 
production. 

investment  at  — 

4% 

5% 

6% 

7% 

8% 

sumption. 

i    to          15 

$4692 

$146 

$334 

$381 

$427 

$474 

$521 

IS                       25 

2168 

96 

183 

204 

226 

248 

269 

25                 5° 

1663 

59 

I25 

142 

J59 

175 

192 

50                100 

1209 

46 

94 

106 

119 

I3I 

143 

100                150 

1010 

37 

77 

88 

98 

108 

118 

150             250 

858 

33 

67 

76 

84 

93 

IO2 

250             500 

645 

25 

5i 

57 

64 

70 

77 

500           750 

632 

23 

48 

55 

61 

67 

74 

750              1000 

640 

20 

46 

52 

58 

65 

71 

1000              5000 

622 

18 

43 

49 

55 

62 

68 

5000            10000 

600 

*7 

4i 

47 

53 

59 

65 

i  oooo  and  over 

568 

16 

39 

44 

5° 

56 

61 

1 

The  cost  of  production  of — 

Gravity  plants  150  to  10,000  million  gallons  and  over  is  80  to  60  per 
cent  of  stated  cost  of  production. 

Pumping-plants  1000  to  over  10,000  million  gallons  of  high-grade 
engines  pumping  water  once,  as  tabulated. 

Pumping-plants  1000  to  over  10,000  million  gallons  of  high-grade 
engines  pumping  water  twice,  add  40  per  cent  to  tabulated  cost  of  pro- 
duction. 

Pumping-plants  100  to  750  million  gallons  of  medium-grade  engines 
pumping  water  twice,  add  40  per  cent  to  tabulated  cost  of  production. 

TABLE  VI. — AVERAGE  COST  OF  FUEL  FROM  REPORT  OF  COMMISSIONER  OP 

LABOR. 


1 

Annual  consumption 
in  million  gallons. 

Cost  of  coal 
per  ton. 

Annual  consumption 
in  million  gallons. 

Cost  of  coal 
per  ton. 

i     to         5 

$2.  14 

150     to          175 

$1.59 

5                10 

2-59 

175                           2OO 

2.15 

10                15 

2.51 

2OO                           250 

2.46 

15                20 

2.36 

250                           500 

2-27 

20                        25 

2.52 

500                           750 

2.32 

25                5° 

2.22 

750                 1000 

2.09 

50                75 

2.36 

1000                5000 

2  .26 

75              ioo 

2.16 

5000              10000 

2.64 

100               125 

2  .02 

10,000  and  over 

2.29 

125          150 

2.66 

result  should  be  reduced  to  a  sliding  scale  of  cost  per  1000  gal- 
lons of  water,  for  application  as  a  tariff  upon  the  water  service 


408  FRANCHISE.     WATER  RATES.    DEPRECIATION. 

of  individual  consumers  in  proportion  to  the  amount  of  water 
consumed. 

The  matter  of  depreciation  resulting  from  the  deterioration  of 
physical  property  should  be  considered  in  relation  to  plants  under 
municipal  ownership  and  administration  as  well  as  those  under 
private  ownership  and  control.  Unless  proper  provision  is  made 
for  the  maintenance  of  the  property  under  either  kind  of  owner- 
ship and  administration,  that  is  to  say,  provision  for  the  losses 
incident  to  physical  deterioration,  there  must  necessarily  be  a 
progressive  shrinkage  of  value,  for  which  there  is  no  tangible 
equivalent.  Provision  of  this  character  must  come  from  some 
definite  source,  when  the  physical  property  subject  to  deteriora- 
tion is  assembled  into  a  mechanical  unit  for  a  definite  purpose, 
as  for  the  production  and  sale  of  a  commodity.  Evidently  the 
income  from  the  sale  of  that  commodity  must  be  the  source 
from  which  is  derived  the  revenue  with  which  to  operate  and 
maintain  the  physical  property.  If  it  is  necessary  to  expend 
money  in  addition  to  that  expended  in  the  construction  of  the 
physical  property,  in  order  to  make  a  market  for  the  commodity 
in  such  amount  and  at  such  a  price  as  to  secure  an  income  suffi- 
cient to  operate  and  maintain  the  physical  property  and  pay 
interest  upon  the  investment  therein,  the  amount  of  money  so 
expended  is  a  cost  of  establishing  the  business.  Income  eventu- 
ally derived  from  the  sale  of  the  commodity  which  is  in  excess 
of  that  needed  to  support  the  physical  property  in  the  manner 
indicated  and  to  pay  interest  upon  the  money  expended  in  estab- 
lishing the  business  is  an  asset  against  which  negotiable  paper 
of  some  sort  may  be  and  usually  is  issued  in  a  purely  private 
and  unrestricted  undertaking  in  some  definite  amount,  which 
possesses  value  in  the  commercial  market  of  an  amount  depend- 
ing upon  the  interest  or  dividends  which  the  excess  income  will 
support.  Frequently  a  portion  of  this  excess  income  is  first 
set  aside  as  a  surplus  fund  available  for  emergency  expenses  or 
as  a  substitute  for  the  capitalization  represented  by  the  negoti- 
able paper  and  the  remainder  only  applied  to  dividends. 

In  the  case  of  a  public-service  corporation,  depending  upon  a 
franchise  for  the  right  to  construct  and  operate  works   for  the 


FRANCHISE.     WATER  RATES.     DEPRECIATION.  409 

production  and  sale  of  a  commodity  at  some  fixed  rate,  the  capi- 
talization of  the  excess  income  as  before  described  is  sometimes 
termed  franchise  value.  However,  under  a  limited  franchise  con- 
taining express  provision  of  the  grantor's  right  to  purchase  and 
an  implied  intention  of  purchase  at  some  stated  interval  or  at 
the  expiration  of  the  franchise,  it  is  often  asserted  that  securi- 
ties representing  purely  capitalized  income  should  have  but  a 
limited  circulation  in  the  financial  market  at  any  time,  as  they  may 
have  no  value  at  the  expiration  of  the  franchise  or  an  indefinite 
value  at  a  time  of  purchase  before  the  expiration  of  the  franchise. 
It  is  also  maintained  that  the  public  as  a  grantor  of  a  franchise 
receiving  no  compensation  for  the  gift  should  not  be  expected 
much  less  required  to  buy  back  the  franchise  at  the  time  of  the 
purchase,  particularly  at  the  expiration  of  the  period  covered  in 
the  grant.  Claim  is  also  made,  with  regard  to  the  rates  under 
which  water  is  dispensed  as  a  commodity  by  a  public  water-service 
corporation,  that  they  were  never  intended  to  accumulate  more 
income  than  is  necessary  to  pay  operating  expenses  and  to  pro- 
vide a  reasonable  fund  for  interest  upon  and  maintenance  of  the 
investment,  and  that  any  income  in  excess  of  this  should  be  con- 
sidered the  result  of  the  use  of  an  excessive  water  rate,  and  accord- 
ingly should  be  applied  to  the  liquidation  of  the  investment,  or 
the  water  rates  should  be  proportionately  reduced. 

The  fact  is  when  water-works  franchises  were  granted  years 
ago  little  thought  was  expended  upon  matters  of  this  kind,  the 
municipality  desired  the  water  service,  and  private  individuals 
were  ready  to  accept  the  obligation  of  supplying  municipalities 
and  to  speculate  somewhat  upon  the  venture.  What  income 
the  water  rates  would  return  was  largely  speculative,  aside  from 
the  fixed  income  of  hydrant  rent.  The  question  of  franchise 
value  as  applied  to  water-service  corporations  becomes  there- 
fore a  question  of  the  moment  and  of  the  occasion,  susceptible  of 
consideration  in  some  instances  and  of  none  in  others,  depending 
largely  upon  the  terms  of  the  franchise  ordinance  itself  and  the 
legality  of  and  equity  in  claims  of  this  character. 

It  is  perfectly  evident  that  the  proper  support  and  main- 
tenance of  the  physical  property  is  of  first  consideration  and 
that  there  can  be  no  consideration  of  franchise  value  whatever, 


410  FRANCHISE.     WATER  RATES      DEPRECIATION. 

assuming  the  validity  of  such  a  claim  to  be  open  to  considera- 
tion, until  adequate  provision  shall  have  been  made  from  the 
income  for  the  support  and  maintenance  of  physical  property. 

It  is  clear  that  if  a  water-works  property  is  appraised  at  a 
valuation  based  upon  the  cost  of  reproduction  less  depreciation, 
there  should  be  more  than  presumptive  evidence  that  the  income 
has  been  sufficient  to  reimburse  the  seller  for  the  losses  which 
this  method  of  valuation  entails,  as  well  as  a  fair  interest  upon 
the  investment.  Information  regarding  original  cost  and  income 
and  current  expenses  is  not  always  available,  and  in  the  absence 
of  proper  and  substantial  information  of  this  character  approxi- 
mations only  can  be  made,  based  upon  general  information  of  a 
similar  character. 

Although  only  the  depreciation  resulting  from  deterioration 
of  the  physical  property  has  been  mentioned,  the  depreciation 
resulting  from  a  gradual  deterioration  of  service  is  also  open  to 
consideration.  But  a  marked  distinction  should  be  made  in 
the  two  types  of  depreciation.  The  former  type  of  depreciation 
results  solely  from  physical  deterioration,  the  latter  type  relates 
to  the  earnings  and  represents  depreciation  of  the  business  or 
"going  value"  of  the  water-works  property.  The  one  relates 
to  elements  entering  the  construction  of  the  water- works,  the 
other  relates  to  elements  of  business  management  in  dispensing 
the  water  service  and  in  providing  the  necessary  means  for  the 
proper  dispensation  of  this  service.  While  the  deterioration  of 
service  may  at  times  result  from  an  incapacity  of  the  physical 
property,  still  the  measure  of  that  deterioration  can  only  be  made 
through  its  depreciating  effect  upon  the  earnings  resulting  from 
the  operation  of  the  plant.  In  illustration  of  this  principle  a 
water-works  plant  which  through  the  lapse  of  years  develops 
an  incapacity  or  deficiency  in  part  or  as  a  whole,  which  is  mani- 
fest through  imperfect  or  inadequate  service,  is  subject  to  a  charge 
upon  its  earnings  over  and  above  operating  expenses  of  an  amount 
which  will  pay  interest  upon  and  maintain  the  investment  re- 
quired in  reinforcing  the  deficient  part  or  parts  of  the  plant. 

The  earnings  are  also  similarly  chargeable  with  an  amount 
which  will  support  properly  the  investment  in  and  the  operation 
of  purification  works  needed  to  purify  water  from  a  source  of 


FRANCHISE.     WATER  RATES.     DEPRECIATION.  4*  I 

supply  which,  though  originally  producing  an  acceptable  and 
wholesome  water,  has  through  the  lapse  of  years  become  polluted 
through  unpreventable  sources  or  influences,  or  water  from  a 
supply  which  originally  required  purification,  but  which  is  inade- 
quately purified  through  neglect  to  extend  the  purification  works 
as  needed,  or  through  an  effort  to  reduce  operating  expenses  at 
the  expense  of  the  water  service. 

The  converse  of  this  situation  is  also  true.  The  earnings  of 
a  business  which  does  not  properly  support  the  original  investment, 
together  with  that  needed  from  time  to  time  to  reinforce  the 
plant  and  to  maintain  an  efficient  service,  should  receive  in  them- 
selves  reinforcement  through  an  increase,  if  necessary,,  of  the 
schedule  of  charges  for  the  water  service. 

Considerations  of  this  character  are  particularly  necessary 
when,  for  any  reason,  an  effort  is  made  to  reach  a  commercial 
value  of  a  property  through  a  capitalization  of  net  earnings. 
A  neglect  to  observe  them  is  particularly  liable  to  result  in  over- 
valuation of  a  property  appraised  at  or  near  the  expiration  of  a 
limited  franchise,  and  may  in  other  instances  result  in  under- 
valuation, when  the  actuating  policy  of  the  management  is  to 
reinforce  and  build  in  anticipation  of  future  requirements. 

Attempts  are  made  to  harmonize  both  types  of  deterioration 
by  basing  estimates  of  depreciation  upon  the  serviceable  life 
of  the  materials  of  construction  as  assembled  in  units  rather  than 
upon  the  actual  physical  life  of  the  materials,  independent  of 
the  useful  life  of  the  respective  units  into  which  they  may  be 
assembled.  The  serviceable  life  is  shorter  than  the  physical  life 
in  amounts  depending  upon  the  actual  conditions  and  require- 
ments of  service. 

There  are  three  methods  of  computing  depreciation  which 
have  had  more  or  less  extended  application — each  method  recog- 
nizing progressive  physical  deterioration. 

The  first  method  assumes  a  certain  annual  rate  of  depreciation, 
and  computes  the  annual  depreciation  for  each  year  upon  the 
original  investment.  For  instance,  assume  a  rate  of  depreciation 
of  2  per  cent  per  annum — which  is  equivalent  to  an  assumed 
physical  life  of  fifty  years — then  the  annual  depreciation  for 
each  $1000  of  investment  by  this  method  becomes  $20  and  for 
twenty  years  is  8400. 


412  FRANCHISE.     WATER  RATES.     DEPRECIATION. 

This  method  of  computation  takes  no  account  whatever  of 
the  interest  earning  capacity  of  the  $20  annuities  for  each 
$1000  of  investment  during  the  interval  for  which  the  deprecia- 
tion is  estimated.  If  these  $20  annual  payments  were  con- 
sidered as  an  annuity,  drawing  interest  at  the  rate  of  2  per  cent 
per  annum,  it  would  amount  to  $1692  for  each  $1000  of  the  orig- 
inal investment  at  the  end  of  fifty  years.  Accordingly  an  appor- 
tionment annually  of  $20  per  $1000  investment  from  the  gross 
earnings,  and  likewise  the  water  rate  which  support  such  an 
annual  apportionment  of  funds,  becomes  excessive. 

If  depreciation  is  estimated  on  this  basis,  it  should  be  con- 
sidered that  the  annual  payments  are  immediately  applied  as 
partial  payments  on  the  original  investment  and  the  interest- 
bearing  portion  thereof  accordingly  reduced.  For  instance, 
assume  the  $1000  valuation  upon  which  the  depreciation  has 
been  computed  to  draw  6  per  cent  interest,  then  the  increment 
by  which  the  annual,  interest  would  be  decreased,  assuming  the 
$20  annual  payments  to  be  immediately  applied  to  payments 
on  the  original  principal,  is  6  per  cent  of  $20  or  $1.20,  and  if 
this  latter  amount  should  be  considered  as  an  annuity,  it  would 
have  to  be  invested  at  about  8  per  cent  to  amount  to  the  differ- 
ence between  the  $1692,  the  amount  of  the  $20  annuity,  and  $1000, 
the  original  investment,  or  at  a  proportionately  higher  rate  of 
interest  for  a  3  per  cent  investment,  etc.  Evidently  this  method 
calls  for  too  heavy  a  rate  of  depreciation,  and  for  an  application 
of  the  annual  payments  not  usually  made. 

The  second  method  of  computing  depreciation  assumes  some 
rate  of  depreciation,  as  in  the  preceding  case,  but  computes  the 
depreciation  on  the  principal  of  the  preceding  year  instead  of 
on  the  original  investment  continuously.  For  instance,  the 
assumed  rate  of  depreciation  of  2  per  cent  a  year  would  run 
as  follows  per  §1000  investment: 

Unpaid 
principal. 

End  of  first           year  $1000 .  oo  X  o .  02  =  $20 .  oo  $980 .  oo 

"     "  second  980.00X0.02=   19.60  960.40 

third  960.40X0.02=   19.21  941.19 

twentieth     "  681.23X0.02=   13.62  667.61 

fiftieth  371.60X0.02=     7.43  364.17 


<C  (  C 

<  c       II 


FRANCHISE.     WATER  RATES.     DEPRECIATION.  4*3 

We  find,  therefore,  at  the  end  of  twenty  years  the  depreciation 
is  $1000.00  — $667.61  =  $332.39,  instead  of  $400.00  by  the  pre- 
ceding method. 

The  principle  upon  which  this  method  of  computation  is 
based  is  that  the  present  value  of  a  property  at  the  end  of  any 
interval  is  that  sum  which  if  the  interest  on  it  at  some  selected 
rate  be  compounded  annually,  it  will  at  the  end  of  the  chosen 
interval  of  time  equal  the  original  investment.  Theoretically, 
therefore,  there  must  always  be  some  present  value  to  an  invest- 
ment in  perishable  property,  and  as  the  depreciation  is  computed 
as  the  difference  between  this  value  and  the  original  investment 
it  can  never  equal  the  investment.  Effort  has  been  made  to  over- 
come the  apparent  inconsistency  of  this  method  of  computing 
depreciation  by  making  computations  upon  the  sinking-fund 
basis. 

The  third  method  of  computation  upon  a  sinking-fund  basis 
assumes  a  life  for  the  physical  property,  computes  the  annuity 
which  at  some  stated  rate  of  interest  will  equal  the  investment, 
and  then  the  amount  of  this  annuity  for  that  portion  of  the  ex- 
pired physical  life  which  may  be  under  consideration.  For 
instance,  assume  the  physical  life  to  be  fifty  years  and  rate  of 
interest  2  per  cent,  then  $11.82  is  found  to  be  the  annuity  for 
each  $1000  of  investment  and  the  amount  of  this  annuity  for 
an  expired  interval  of  twenty  of  the  fifty  years  becomes  $287 
per  $1000,  the  amount  of  the  depreciation,  or,  if  considered  on  a 

3  per  cent  basis,  the  depreciation  becomes  $239,  or  $197  on  a 

4  per  cent  basis. 

This  method  contemplates  refunding  the  investment  at  the 
end  of  some  specific  period,  the  duration  of  which  depends  upon 
the  rate  of  deterioration  of  the  physical  property  tinder  con- 
sideration and  an  investment  of  the  money  set  apart  for  this 
purpose  in  productive  property  or  securities.  The  method  is 
similar  to  that  provided  by  law  for  the  extinguishment  of  munici- 
pal, state,  and  national  debts,  and  is  being  extensively  employed 
in  the  valuation  of  water- works  properties. 

In  order  to  apply  this  method  of  estimating  depreciation,  a 
sinking-fund  table  (pp.  414,  415)  is  given  showing  the  annuity 
required  to  redeem  one  dollar  at  rates  of  interest  varying  from 


414 


FRANCHISE.     WATER  RATES.     DEPRECIATION. 


TABLE  VII. — SINKING-FUND  TABLE  FOR  i  TO  100  YEARS  AT  STATED  RATES 

OF   INTEREST. 


Year. 

Rates  of  interest  in  per  cent. 

3% 

**% 

3% 

3i% 

4% 

i 

$1  .OOOOO 

$1  .OOOOO 

$1  .  OOOOO 

$1  .00000 

$1  .OOOOO 

2 

o  495°5 

0.49382 

o  .49261 

0.49140 

0.49020 

3 

0.32675 

0.32514 

0-32353 

0.32193 

0.32035 

4 

0.24262 

o.  24082 

0.23902 

0.23725 

0.25550 

5 

o.  19218 

o  19025 

0.18835 

0.18648 

0.18463 

6 

0.15853 

0-15655 

O.I5451 

o.  15267 

0.15077 

7 

Q.I3451 

0.13250 

o.  13051 

o.  12854 

o.  12661 

8 

0.11651 

o.  11458 

o.  11246 

o  .  11048 

0.10853 

9 

o.  10252 

o.  10046 

0.09843 

0.09644 

o  .  09449 

10 

0.09133 

0.08926 

0.08723 

0.08524 

0.08329 

ii 

0.08218 

0.08011 

0.07808 

0.07609 

0.07411 

12 

0.07456 

o.  07250 

0.07047 

0.06848 

0.06655 

J3 

0.06812 

0.06605 

0.06403 

0.06205 

0.06015 

14 

o.  06260 

0.06054 

0.05853 

0.05657 

0.05467 

15 

0.05782 

o  05577 

0.05380 

o  05183 

0.04994 

16 

0.05365 

0.05160 

0.04961 

0.04768 

0.04582 

J7 

0.04997 

0.04793 

0.04595 

o  04404 

0.04220 

18 

0.04670 

o  04470 

0.04271 

0.04082 

o  03899 

19 

0.04378 

0.04176 

o  03981 

0.03794 

0.03614 

20 

0.04116 

0.03915 

0.03722 

o  03536 

0.03356 

21 

0.03878 

0.03678 

o  03487 

0.03304 

0.03128 

22 

0.03663 

0.03465 

0.03270 

o  03094 

0.02920 

23 

0.03467 

0.03270 

0.03081 

0.02902 

0.02731 

24 

0.03287 

o  03091 

0.02905 

o  02727 

0.02560 

25 

0.03122 

0.02928 

0.02743 

0.02567 

o  .02401 

26 

o.  02970 

0.02777 

0.02594 

0.02421 

0.02257 

27 

0.02821 

o  .  02640 

o  02460 

o  02285 

0-02124 

28 

0.02699 

o  .  02509 

0.02329 

o.  02161 

O.O2OOO 

29 

0.02578 

0.02389 

O.O22II 

0.02045 

0.01888 

3° 

0.02465 

0.02278 

O.O2IO2 

0.01937 

0.01783 

3i 

0.02360 

o.  02174 

O.O2OOO 

0.01837 

0.01686 

32 

o.  02261 

0.02077 

0.01905 

0.01744 

0.01595 

33 

0.02169 

0.01986 

o.  01816 

0.01657 

0.01511 

34 

0.02082 

0.01901 

0.01732 

0.01576 

0.01431 

35 

O.O2OOO 

o.  01821 

o  01654 

0.01499 

0.01358 

36 

0.01923 

0.01745 

0.01580 

o  01426 

0.01288 

37 

0.01851 

o.  01674 

O.OI5II 

o  01361 

0.01224 

38 

0.01781 

0.01607 

O.OI450 

0.01298 

o  01163 

39 

0.01717 

0.01544 

0.01383 

0.01240 

o.  01106 

40 

0.01655 

0.01484 

0.01326 

0.01183 

0.01052 

4i 

0.01597 

o.  01427 

O.OI27I 

o.  oi  130 

0  .OIOO2 

42 

0.01542 

0.01373 

O.OI2I9 

0.01080 

o  .00954 

43 

0.01489 

0.01322 

O.OII70 

0.01033 

0.00909 

44 

0.01439 

0.01273 

O.OII23 

o  .00987 

0.00866 

45 

0.01391 

o.  01226 

O.OIO8O 

0.00945 

0.00826 

46 

0.01345 

0.01183 

O.OIO36 

o.  00905 

o  00788 

47 

0.01302 

0.01141 

0.00996 

o  .00866 

0.00752 

48 

0.01260 

o  .01097 

0.00957 

0.00830 

0.00718 

49 

0  .OI22O 

0.01066 

O.OO9I8 

0.00796 

0.00686 

5° 

o  .01182 

0.01026 

0.00886 

0.00763 

0.00655 

FRANCHISE.     WATER  RATES.     DEPRECIATION. 


4'5 


TABLE  VII. — SINKING-FUND  TABLE  FOR  i  TO  100  YEARS  AT  STATED  RATES 
OF   INTEREST. — Continued. 


Year. 

Rates  of  interest  in  per  cent. 

2% 

2*% 

3% 

3i% 

4% 

51 

$0.01146 

$0.00991 

$0.00853 

$0.00732 

$0.00626 

52 

O.OIIH 

O.OO957 

O.OO822 

0.00703 

0.00598 

53 

0.01077 

0.00925 

0.00791 

0.00674 

0.00572 

54 

0.01045 

0.00894 

0.00763 

0.00647 

0.00547 

55 

0.01014 

o  00866 

0.00735 

O.OO622 

0.00523 

56 

0.00984 

0.00837 

0.00709 

0.00597 

0.00501 

57 

0.00956 

0.00810 

0.00683 

o  00573 

0.00479 

58 

0.00929 

0.00784 

0.00659 

0.00550 

0.00458 

59 

0.00902 

0.00759 

0.00635 

0.00529 

0.00439 

60 

0.00877 

0.00735 

0.00613 

0.00507 

0.00420 

61 

0.00852 

0.00712 

0.00592 

0.00489 

0.004O2 

62 

0.00828 

0.00690 

0.00571 

0.00471 

0.00385 

63 

0.00806 

0.00669 

0.00552 

0.00453 

0.00369 

64 

0.00784 

0.00648 

0.00533 

0.00435 

o  00353 

65 

o  00763 

0.00628 

0.00515 

0.00418 

0.00339 

66 

0.00742 

0.00609 

0.00497 

0.00403 

0.00325 

67 

0.00722 

0.00591 

0.00480 

0.00388 

0.003II 

68 

0.00704 

0.00573 

0.00465 

0.00373 

0.00298 

69 

0.00685 

0.00556 

0.00449 

0.00359 

O.OO286 

70 

0.00667 

o.  00540 

0.00434 

0.00346 

o.  00274 

71 

0.00649 

0.00524 

0.00419 

0.00333 

0.00263 

72 

0.00633 

0.00508 

0.00405 

O.OO32I 

0.00252 

73 

0.00616 

0.00493 

0.00392 

0.00309 

0.00242 

74 

0.00601 

0.00479 

0.00379 

0.00298 

0.00232 

75 

0.00585 

0.00465 

0.00367 

0.00287 

0.00223 

76 

0.00571 

0.00452 

0.00355 

O.OO277 

0.00214 

77 

0.00557 

0.00439 

0.00343 

0.00266 

0.00205 

78 

0.00542 

0.00426 

0.00333 

O.OO257 

0.00197 

79 

0.00529 

0.00414 

O.OO32I 

O.OO247 

0.00189 

80 

0.00516 

0.00403 

O.OO3II 

O.OO239 

0.00181 

81 

0.00503 

0.00391 

O.OO3OI 

O.OO23O 

0.00174 

82 

0.00491 

0.00380 

O.OO292 

O.OO222 

0.00167 

83 

0.00479 

0.00369 

0.00282 

O.OO2I4 

0.00160 

84 

0.00468 

0.00359 

0.00273 

O.OO2O6 

0.00154 

85 

0.00456 

0.00349 

0.00264 

O.OOI99 

0.00148 

86 

0.00445 

0.00340 

0.00256 

O.OOI92 

0.00142 

87 

0.00434 

0.00330 

0.00248 

O.OOI85 

0.00136 

88 

0.00424 

0.00321 

0.00240 

0.00178 

0.00131 

89 

0.00414 

0.00312 

0.00233 

O.OOI72 

0.00126 

go 

" 

0.00405 

0.00304 

O.OO225 

O.OOl66 

O.OOI2I 

91 

0.00395 

0.00295 

O.OO2I9 

O.OOI6O 

o.  00116 

7 

92 

0.00386 

0.00287 

O.OO2I2 

O.OOI54 

O-OOIII 

93 

0.00377 

0.00280 

O.OO2O5 

O.OOI49 

O.OOIO7 

94 

0.00368 

0.00271 

O.OOI99 

O.OOI44 

O.OOIO3 

95 

0.00360 

0.00265 

0.00193 

O.OOI38 

0.00099 

96 

0.00351 

0.00258 

O.OOI87 

O.OOI34 

O.OOO95 

97 

0.00343 

0.00251 

O.OOlSl 

O.OOI29 

O.OOO9I 

98 

" 

0.00336 

0.00244 

O.OOI75 

O.OOI25 

O.OOO87 

99 

0.00328 

0.00237 

O.OOI7O 

O.OOI2I 

O.00084 

IOO 

0.00320 

0.00231 

0.00165 

o.  00116 

O.OOoSl 

416  FRANCHISE.     WATER  RATES.     DEPRECIATION. 

2  to  4  per  cent  and  for  an  interval  of  one  to  one  hundred  years, 
the  deposit  being  made  at  the  end  of  each  year. 

The  amount  of  an  annuity  of  one  dollar  for  any  particular 
period  and  rate  of  interest  is  the  reciprocal  of  the  corresponding 
amount  in  the  table.  Accordingly  in  finding  depreciation  for  a 
period  of  twenty  years,  for  instance,  on  a  2  per  cent  basis,  of 
property  possessing  a  life  of  fifty  years,  divide  the  annuity  which 
will  redeem  the  investment  in  fifty  years  by  0.0412 — which  per 
$1000  is  $11. 82-^-0.0412  =  $287. 

The  rate  of  interest  at  which  annuities  to  a  sinking-fund 
may  be  invested  should  vary  inversely  as  the  life  of  the  article 
of  which  the  depreciation  is  sought,  or  approximately  as  follows: 

For  a  life  of  100  years   2  per  cent 

"     "     "      "     80        "         2i 

"     "     "      "     60        "         2|         " 

It         II        (  (          I  t  .  H  _  (  C 

"   "  "    "  30     "     3}     •" 

<c      cc      cc       «      2Q          C(  3j 

«         C  t        «          <  t         -.-  «  (  ._£  tl 

it         C  C        it          C  C         _  C  C  C  ( 

10  4 

In  order  to  show  the  application  of  Table  VII,  the  experience 
of  a  small  city  may  be  offered  as  an  example: 

Original  cost  of  physical  property $56000 .  oo 

Capacity  in  million  gallons  per  year 37 

Average  investment  per  million  gallons  annual  consumption. ,  .  .     $1540.00 

Average  working  pressure 80  pounds 

All  water  pumped  twice  with  the  ordinary  grade  of  pumping-engines 
and  filtered. 


i. .Average  cost  of  production  of  a  water  service  of  37  million 

gallons  per  year,  Table  V $59 .  oo 

2.  Add  for  double  pumping  and  filtering 24.00 

3 .  Add  for  station  expenses,  exclusive  of  salaries  required  to  pump 

against  20  pounds  excess  pressure 10 .  oo 

4.  Add  i£  per  cent  of  the  average  investment  per  million  gallons 

annual  consumption  for  surplus  to  meet  emergency  ex- 
penses and  to  provide  for  renewals. 23 .  oo 

Total,  exclusive  of  interest,  taxes,  and  sinking-fund $116.00 


FRANCHISE.     WATER  RATES.     DEPRECIATION.  417 

The  estimated  cost  of  n.6  cents  per  one  thousand  gallons 
would  usually  be  exceeded  during  the  period  that  the  town  re- 
ferred to  is  gradually  approaching  the  rate  of  consumption  of 
37  million  gallons  per  year  and  similarly  reduced  as  the  annual 
consumption  exceeds  the  37  million  gallons. 

Tables  III,  IV,  and  V  may  be  employed  as  an  aid  to  munici- 
palities desiring  to  rate  the  water  service  of  a  new  water-works 
or  to  rerate  the  water  service  of  a  recently  purchased  water-works. 
An  actual  case  of  a  water-works  plant  owned  and  operated  by  a 
municipality  is  offered  to  illustrate  the  distribution  of  revenue 
from  the  sale  of  water  service. 

Average  annual  consumption  in  million  gallons 385.40 

Investment  per  million  gallons  annual  consumption $1200.00 

Cost  of  fuel  per  ton 4 .  oo 

Average  pressure  in  city 80  pounds 

Pumping-engine  duty  in  million  foot-pounds 33 

Per  million 
gallons. 

The  actual  cost  of  production,  including  the  necessary'expenditure 

for  maintaining  the  service $59 .  oo 

The  amount  of  interest  at  4  per  cent  paid  on  the  existing  balance 

of  the  original  cost  of  construction 26 .  oo 

The  amount  applied  to  sinking-fund  to  redeem  the  bonds  repre- 
senting the  unpaid  cost  of  construction  is  about 

The  amount  applied  to  reinforcement  and  similar  current  expenses 

Gross  income $i  1 7 .  oo 

The  city  has  been  forty  years  in  paying  off  about  50  per  cent 
of  the  cost  of  constructing  the  water-works,  and  during  the  interval 
has  maintained  the  plant  generally  in  an  efficient  condition,  but 
deterioration  of  the  source  of  water-supply  has  reached  such  a 
stage  that  purification  works  are  now  required  at  an  estimated 
cost  of  construction  of  nearly  $60,000,  without  prospects  of  any 
corresponding  increase  of  earning  capacity  of  the  water-works, 
but  with  a  proportionate  increase  of  the  cost  of  operation  and 
of  the  current  expenses  of  maintenance. 

This  example  illustrates  both  a  successful  management  and 
the  advisability  of  maintaining  water  rates  considerably  above 
the  cost  of  production,  in  order  to  provide  for  emergencies  of  ser- 
vice and  reinforcements  as  the  necessity  arises  from  time  to 


FRANCHISE.     WATER  RATES     DEPRECIATION. 

time.  The  example  affords  additional  illustration  of  a  city  treat- 
ing the  water  service  on  a  commodity  basis  and  accordingly 
charging  the  income  from  consumers  for  interest  and  sinking- 
fund,  and  at  the  same  time  charging  the  city  annually  over  $6000 
for  the  public  use  of  the  water  service. 

Assuming  the  city  to  have  purchased  the  property  at  its  cost 
of  $1200  per  million  gallons  annual  consumption,  and  desiring 
to  rerate  the  water  service  through  the  use  of  the  table,  it  might 
proceed  as  follows: 

Per  million 
gallons. 

Average  cost  of  production,  Table  V $25 .  oo 

Add  cost  of  fuel  above  average  cost  and  of  maintaining  the  pres- 
sure of  water  service  above  average  and  a  small  percentage 
of  double  pumping,  25X53^X1$ 20.00 


Interest  on  investment  at 

Sinking-fund  at  3  per  cent  to  redeem  the  investment  in  about  50 

years,  as  per  Table  VII 

Contingent  expenses  of  operation  and  maintenance 

Total  per  cent 6 .40% 

Thence  by  Table  V  opposite  $1209  investment  under  6  per 
cent  column  take  119,  deduct  the  corresponding  tabulated  cost 

of  production  of  $46,  multiply  by  -^-,  add  $45,  the  cost  of  pro- 
duction estimated  above  equals  $123  per  million  gallons  as  a 
fair  base  rate  for  the  stated  conditions,  which  base  rate  should 
be  so  apportioned  among  the  consumers  as  to  produce  a  gross 
annual  income  of  about  $47,400.  But,  in  the  event  of  the  con- 
struction of  a  filter,  the  expenditure  before  stated  of  $60,000 
must  be  supported  by  the  earnings  to  the  extent  of  6.4  per  cent 
on  the  investment  for  interest,  sinking-fund,  etc.,  and  operating 
expenses  provided  for  to  the  amount  of  about  $2  per  million 
gallons,  aggregating  about  $12  per  million  gallons,  making 
the  corresponding  base  rate  $135  per  million  gallons,  and  the 
gross  annual  income  a  little  more  than  $52,000.  This  base  rate 
and  accordingly  the  gross  income  may  be  lowered  progressively 
as  the  sinking-fund  is  applied  in  the  redemption  of  the  original 
investment. 


FRANCHISE.     WATER  RATES.     DEPRECIATION.  4*9 

In  many  instances  the  base  rate  thus  obtained  should  be 
corrected  by  some  amount  corresponding  to  the  losses  of  water 
unavoidably  taking  place  between  the  source  of  water-supply 
and  the  faucet  of  the  consumer,  particularly  where  the  use  of 
pumps  is  necessary  in  the  distribution  of  the  water  service.  These 
losses  between  the  pumps  and  the  faucet  of  a  consumer  often 
amount  to  fully  25  per  cent  of  the  water  registered  as  delivered 
by  the  pumps.  In  other  words,  for  every  1000  gallons  of  water, 
pump  delivery,  there  is  750  gallons,  faucet  delivery.  Accordingly 
a  base  rate  per  million  gallons,  estimated  upon  the  basis  of  pump 
delivery,  should  often  be  increased  by  about  one-third  in  order 
to  get  a  proper  value  for  the  water  service  per  million  gallons 
at  the  faucet. 

Where  the  law  provides  that  the  property  shall  be  taxed  for 
the  interest  and  sinking-fund  of  the  bonds  issued  in  construction 
or  purchase  of  water-works,  the  gross  income  should  exceed  the 
cost  of  production  by  an  amount  equivalent  to  from  ij  to  2  per 
cent  of  the  investment,  in  order  to  provide  the  surplus  usually 
needed  to  a  greater  or  less  extent  in  meeting  contingent  expenses 
of  operation  and  in  the  repairs,  reinforcement,  and  maintenance 
of  the  water-works  property. 

The  foregoing  illustrations  are  further  intended  to  caution 
those  who  may  have  occasion  to  use  the  table  relating  to  the 
cost  of  producing  the  water  service  to  do  so  guardedly,  in  view 
of  the  fact  that  they  represent  general  averages  and  that  the 
tabulated  computations  must  receive  proper  correction  in  order 
to  render  them  applicable  to  a  specific  case.  In  this  manner 
they  may  prove  of  assistance  to  the  judgment,  when  definite 
data  of  a  similar  character  is  not  available. 

In  summing  up  what  has  been  said  about  water  rates,  it  may 
be  said  that  the  base  rate  should  embrace  the  following  essen- 
tial items,  cost  of  production,  interest  on  investment,  repairs, 
sinking-fund,  unavoidable  losses  of  water,  and  a  surplus  of  an 
amount  or  percentage  depending  upon  the  particular  character 
of  the  system  of  water-works  under  consideration. 


INDEX. 


Absorbing  capacity  of  soils  and  sands, 

43 

Accounts,  361  ff. 
Air-lock,  56 
Air-valves,  292,  293 
Albuminoid  ammonia,  3,  322 
Algicides,  158 
Alkalinity,  observations  of,  146;  ratio 

of,  to  coagulant,  141 
Alterations  and  repairs,  298  ff. 
Ammonia,  albuminoid,  3,  322;  free,  3, 

10,  322 

Analysis  of  water,  154,  322 
Annual  reports,  380  ff. 
Annuities  to  a  sinking-fund,  416 
Appurtenances,  care  of,  280  ff. 
Aquaphone,  338 

Artesian  basin,  amount  of  water  fur- 
nished by,  17 

Artesian  water-supplies,  19 
Artesian  well,  10;  at  Hitchcock,  Tex., 

18;   at  Memphis,  18 
Asphalt,  use  of,  308  ff. 
Average  annual  consumption,  income 

and  cost,  in  water-works  property, 

401,  402,  407 
Average  daily  consumption  of  water 

per  person,  341 

Bacillus  coli,  322 

Bacteria,  2,  4;  harmless  and  danger- 
ous, 167 

Bacterial  examination,  322 

Bacterial  purification,  117 

Bacteriology,  4 

Baffles,  136 

Ball-cock,  greatest  source  of  water 
waste  330 

Base  rate  per  million  gallons  of  water, 
407  418;  items  to  be  embraced 
in,  419 

Basin,  raw-water,  127 

Bathing  in  sources  of  water-supply,  31 1 


Berm,  217 

Bills  for  water,  when  payable,  363 

Boilers,  station  record  of,  191 

Boiling,  134,  135 

Borings  along  Missouri  River,  34 

Boston,  Mass.,  tenement-houses  in,  use 

of  water  in,  327 
Branch,  cutting-in  a,  298 
Branch-sleeve,  split,  299 
Bremen,  Germany,    water-supply  of 

168 
By-pass  pipes,  118 

Calking-hammer,  237 

Calking-iron,  237 

Carbonic  acid  in  natural  waters,  139 

Carelessness  in  use  of  water,  324  ff. 

Casing-tubes  for  strainers,  69  ff. 

Cast  iron  for  mains  of  distribution 
system,  238 

Cast-iron  pipe,  flange-jointed,  for  pipe 
lines,  73;  lead-jointed,  73,  74; 
current  flow  in,  349 

Catchment  area,  characteristics  of,  5, 
6;  danger  of  epidemics  when  in- 
habited, 204;  yield  of  or  run-off 
from,  in  Sudbury,  Wachusett, 
Croton,  Perkiomen,  Neshaminy, 
Tohickon,  226,  227;  sanitary  ex- 
amination of,  320 

Chemical  analysis  of  water,  322 

Chlorine,  4,  8,  322 

Circulation,  127,314;  swinging  motion 
of  water  a  form  of,  136 

Clamp,  305 

Clarification,  116;  by  natural  sedi- 
mentation, 123;  by  the  aid  of  a 
coagulant,  137;  by  natural  sedi- 
mentation and  coagulation,  re- 
sults of,  149;  and  purification,  162 

Clearest  water,  136,  137 

Clearness  and  wholesomeness,  connec- 
tion between,  15 

421 


422 


INDEX. 


Clear-water  basin,  127 ;  plan  of  covered, 

174 

Clogging  capacity  of  a  filter,  102 

Closed-well  construction,  72 

Coagulant  loss  of,  141 ;  time  to  intro- 
duce, 143;  when  not  required,  148 
sulphate  of  alumina  as  a,  148; 
sulphate  of  iron  as  a,  148;  how 
delivered,  149;  methodical  use  of, 
150;  economy  in  use  of,  156; 
hydroxide  of  iron,  natural  coagu- 
lant, 1 60 

Coagulant  apparatus,  149;  daily  par- 
tial analysis  of  water,  154 

Coagulation,  137  ff.,  148;  use  of, 
150;  products  of,  should  be  re- 
moved from  water,  151;  natural, 

159 
Coal,    amount    of,    required    to    raise 

water,  189;  cost  of,  190 
Coal  consumption  in  pumping-engine, 

1 86 
Cochituate,  Lake,  color  of  water  in, 

206  ff. 
Cocks,    corporation,    251;     stop    and 

waste,  252 ;  for  iron  and  lead  pipe, 

252,  253;    "round  way"  type  of, 

253;    compression,   253;    location 

of,  261;  cost  of,  262 
Coefficient  of  porosity  of  natural  sands 

and  gravels,  31 

Coefficient  of  resistance,  values  of,  37 
Color  of  water,  effect  of  long  storage 

on,  205 

Colorado,  irrigated  sections  in,  44 
Commissioner    of    Labor,    Fourteenth 

Annual  Report  of,  401 
Concrete,  to  secure  best  results  with, 

3°9 
Construction  account,   363,   364,   366, 

367 

Construction  plans,  218 
Construction  records,  221 
Consumption,  average,  341,  401,  402, 

407;  domestic,  327 
Consumption,  metered,  326: 

Belmont,  Mass.,  326 

Brockton,  Mass.,  326,  342 

Fall  River,  Mass.,  326,  327,  342 

Lawrence,  Mass.,  342 

London,  England,  327 

Lowell,  Mass.,  342 

Maiden,  Mass.    326,  328 

Milton,  Mass.,  326 

Milwaukee,  Wis.,  342 

Newton,  Mass.,  326,  327,  342 

Providence,  R.  I.,  328,  342 

Reading,  Mass.,  342 

Ware,  Mass.,  326,  342 

Watertown,  Mass.,  326 

Wellesley,  Mass.,  326,  342 


Woonsocket,  R.  I.,  326,  342 
Worcester,  Mass.,  326,  327,  342 
Yonkers,  N.  Y.,  326 
Consumption  where  water  is  paid  for  at 

schedule  rates,  342: 
Braintree,  Mass.,  342 
Buffalo,  N.  Y.,  342 
Cambridge,  Mass.,  342 
Dedham,  Mass.,  342 
Haverhill,  Mass.,  342 
Indianapolis,  Ind.,  342 
Lynn,  Mass.,  342 
Montague,  Mass.,  342 
New  Bedford,  Mass.,  342 
New  Haven,  Conn.,  342 
Salem,  Mass.,  342 
Waltham,  Mass.,  342 
Consumption  of  water  in  cities,  effect 

of  use  of  meters  on,  340 
Continuous-flow    method,     117;     dis- 
placement principle  of,  119;  modi- 
fication of  displacement  principle 
of,  119 

Convection  currents,  133,  151 
Copper-sulphate  treatment,  318 
Corporation  cocks,  251;  cost  of,  262 
Cost,  estimates  of,  245,    average,  401, 
402,  403,  407;    of  production  of 
municipal  and  private  plants,  403 
Coupon  of  water  rate,  362 
Cracked  pipes,  304 
Current   flow,    measurement   of,    348; 

in  cast-iron  pipe,  349 
Currents,  convection,   133,   151;    elec- 
trical, 344  ff. 
Curtain  of  planks,  119 
Cutting-chisel,  237 
Cutting-in  a  branch,  298 
Cutting-in  special,  Dunham,  298 

Dams,  masonry,  216;  rock-fil^  216; 
earth,  216;  New  Croton,  216;  flow 
of  water  over,  226;  leaks  in,  307 

Darcy  formula,  26 

Deacon  waste-water  meter,  332,  333, 

334 

Dead  ends,  319 

Deficit  in  water-works,  395 

Depreciation,  389  ff. ;  from  deteriora- 
tion of  the  physical  property, 
408  ff. ;  from  deterioration  of 
service,  410;  methods  of  com- 
puting, 411  ff. 

Deterioration  of  water-works  property, 
389,  408 

Developing  water-supplies,  i  ff. 

Discharge,  maximum,  57 

Disease  germs  in  water,  source  of,  5 

Disk-piston  meters,  265 

Displacement,  continuous  flow  of  water 
produced  by,  133 


INDEX. 


423 


Displacement  method,  121,  122;  oper- 
ating a  settling-basin  by,  129 

Distribution  reservoirs,  linings  of,  307 ; 
sediment  and  organic  matter  in, 
320 

Domestic  consumption  per  capita  as 
determined  by  meter  measure- 
ment, 327 

Double-trolley  system  and  electrolytic 
action,  350 

Drainage  ditch,  313;  cost  of  construct- 
ing, 313 

Drop-of-potential  method  of  current- 
flow  measurement,  348 

Drop-pipes,  69  ff.,  72;  diameter  of,  80 

Drought,  84 

Drown,  Dr.  T.  M.,  sanitary  water  anal- 
yses, 12,  205 

Dry-v.eather  flow  of  streams,  an  index 
of  the  volume  of  underflow,  41 

Duty,  station  vs.  test,  187,  188 

Duty  guarantee  in  pumping-engines, 
"184  ff.,  199;  penalty  for  non-ful- 
fillment of,  202 

Earnings,    gross,    of    private    plants, 

403 
Electrical  currents,  damage  caused  by, 

344  ff- 

Electrolysis,  343  ff. ;  effect  of,  on  cast- 
iron  water-pipe,  344,  345 

Electrolytic  action,  double-trolley  sys- 
tem and,  350 

Embankments.     See  Dams 

Epidemics  and  catchment  areas,  204 

Estimates  of  cost,  245 

Evaporation  from  a  water-surface, 
measurements  of,  227,  322 

Excavating,  back-filling,  and  pipe- 
laying,  cost  of,  247 

Excavation  of  frozen  material,  302 

Extensions  of  water- works,  232  ff. 

Fill-and-draw  method,  117;  difficulty 
in,  117 

Filter  effluent,  standard  of  purity  of  a, 
163 

Filter-gallery,  49;  development  of,  51; 
depth  of  construction  of,  54;  sub- 
stitute for,  54,  56;  limitation  of, 

53,  54 

Filter  influent,  turbidity  of,  172 
Filter-plant,  mechanical,  121 
Filtered  iron  water,  1 1 2 
Filtered  surface-water,  112 
Filtered  well-water,  112 
Filtering,  English  system  of,  170 
Filters,  clogging  capacity  of,  102;  for 

removing  sewage  pollution,    116; 

mechanical,  161;  efficiency  of ,  162; 

purifying  and  clarifying,  operation 


of,  163;  failures  of  mechanical, 
167;  disappointing  result  of  slow 
sand,  167;  English,  171;  yield  of , 
172;  plan  of  mechanical,  174;  bio- 
logical, 182 

Filtration,  161  ff . ;  rate  of,  161;  clari- 
fying and  purifying,  distinction 
between,  162;  mechanical  and 
slow  sand,  1 8 1 ;  preliminary  prep- 
aration of  water  for,  182 

Financial  management,  366  ff. 

Financial  statements,  381 

Fire-hose,  355,  356 

Fire-hydrants,  355;  care  of,  284;  tool 
for  testing,  285 

Fire  protection,  352  ff. ,  379 

Fire-service,  water  consumed  in,  395; 
efficiency  of,  398,  399,  400 

Fire  streams,  allowance  for,  353;  num- 
ber of,  in  cities,  353-355;  height 
of,  358 

Fisher  governor,  197 

Fixed  solids  in  water,  322 

Flow,  radial,  61 ;  parallel,  84;  uni- 
formity of,  through  filter,  166 

Flow  head,  relation  of,  to  friction  head, 
77 

Flow  of  water,  through  sands  and  sand- 
stone, 31;  through  unassorted 
sands,  36 

Flushing,  320 

Flush-tanks,  sewer,  330;  in  Rich- 
mond, Ind.,  330 

Force  account,  365 

Formulae  relating  to  ground-water 
supply,  6 1  ff. 

Franchise  to  construct  and  operate 
water-works,  385  ff.,  409 

Friction  head,  77 

Friction  losses  in  hose,  359 

Frost -cases,  cost  of,  248 

Frozen  material,  excavation  of,  302 

Fuel,  average  cost  of,  407 

Gage,  pressure  and  recording,  230 

Gallery  and  tubular-well  methods, 
costs  of,  83 

Galveston,  Tex.,  water-supply  of,  7 

Germicides,  117,  158 

Gooseneck,  251 

Gow  meter -clam  ping  device,  272 

Gowing  pipe-jointer,  235 

Gravel,  water-bearing,  51 

Gravity-flow  pipe  connecting  wells,  54 

Ground-water,  an  ideal  drinking-water, 
i ;  basis  of  popular  acceptance  of, 
2 ;  sanitary  analysis  of,  3 ;  general 
superiority  of,  13,  softness  of,  15, 
quantity  of,  16  ff. ;  yield  of,  16, 
velocity  of  flow  of,  16,  develop 
ment  of,  48,  more  desirable  than 


424 


INDEX. 


impure  surface-water,  113  ff. ;  as 
a  natural  coagulant,  160;  removal 
of  iron  from,  160 

Ground-water  curves,  52 

Ground-water  supply,  quality,  i; 
quantity,  16;  stability  of,  16; 
shallow,  19;  conditions  of  Missis- 
sippi River  valley  near  Muscatine, 
la.,  20;  problems  to  be  solved,  23; 
diagram  relating  to,  47 ;  develop- 
ment of,  48 ;  single  open  well,  48 ; 
filter-gallery,  49;  series  of  large 
open  wells,  54;  series  of  small 
tubular  wells,  56,  57;  formulae 
relating  to,  61  ff. 

Ground-water  table,  fluctuations  in, 
27,  28 

Hardness,  temporary,  139;  permanent, 

139,  322 

Hazen- Williams  formula,  358 
Hose,  fire-service,  399,  400 
House-to-house  inspection,  338 
Hydrant  rents,  396,  397,  398 ;  average, 

403 

Hydrants,  233;  post,  239;  flush,  239; 
plug  or  compression,  239;  gate, 
239;  details  to  be  considered  in 
selecting  make  of,  239;  Eddy,  242; 
Chapman,  242 ;  Mathews,  242 ;  Lud- 
low,  243 ;  Corey,  243 ;  Walker,  243 

Hydrate  of  alumina,  135,  139,  151 

Hydrate  of  iron,  1 52,  153 

Hydrological  survey,  42 

Hydroxide  of  iron  as  a  coagulant,  160 

Hygienic  quality  of  water  from  puri- 
fication works,  1 1 2 

Ideal  water,  13 

Improving  water-supplies,  i  ff. 

Income,  average,  401,  402,  407;  gross, 

403 

Income  account,  368 

Infiltration  gallery.     See  Filter-gallery 

Inspection,  338 

Interest,  rate  of,  on  a  water-works  in- 
vestment, 392,  403 

Investment,  private,  interest  on,  392, 

4°3 
Iron,  removal  of,  85  ff. ;    remedy  for, 

86 
Iron  pipe,  cement-lined,  254;   cost  of, 

263 

Iron  water,  filtered,  112 
Irrigated  sections  in  Colorado,  44 
Isochlors,  323 

Johnson  corrugated  steel  rods,  105 
Joint,  cup,   252;    wiped,   252;    solder 

required  for  wiped  and  cup,  264; 

lead,  301 


Kansas  City,  Mo.,  settling-basin  at, 
126,  127;  temperature  of  water 
in  settling-basin,  134 

Kellogg  repair  sleeves,  303 

Laboratory  for  examination  of  water, 
321 

Lead  kettle  and  furnace,  236 

Lead  pipe,  lead-  or  tin-lined,  254,  257; 
precautions,  259;  weights  of,  per 
foot,  263 

Lead-poisoning  resulting  from  water 
drawn  from  lead  service-pipes,  257, 
258 

Leakage,  loss  of  water  through,  325; 
maximum  per  day,  329;  in  Stone- 
ham,  Mass.,  329;  in  Boston,  329, 
330;  how  reduced,  341;  due  to 
electrolysis,  345 

Leaks  in  mam  pipes  or  service  connec- 
tions, 303  ff. ;  causes  of,  306 ;  re- 
pair of,  307 

Lime-water,  treating  river- water  with. 

153 

Location  of  main  valve,  sketch  of,  220 
Loss  of  head  in  cast-iron  pipe,  357 
Losses,  due  to  leakage,  341 ;    due    to 
under-registration  of   service-me- 
ters, 341 

Main,  steel,  repair  of,  304 

Main  pipe-line,  position  of,  232 

Main  valve,  sketch  of  location  of,  220 

Mains  of  distribution  system,  cast  iron 
for,  238 

Maintenance  account,  363,  364,  366,  368 

Maintenance  and  operation  of  water- 
works, 218  ff. 

Maintenance  records,  223 

Manhole  setting  for  large  meters,  275 

Manometer,  332 

Material  account,  365 

Materials,  237  ff. 

Measurement,  plunger  -  displacement 
method  of,  193;  piezometer  meth- 
od of,  1 93 ;  weir  measurement  of,  193 

"Mechanical  efficiency,"  applied  to 
pum  ping-engines,  184 

Melting  out  lead  joints,  301 

Merrimac,  Mass.,  minimum  meter  rates 
of,  375 

Meter-box,  Volkhardt,  275 

Meter-clamping  device,  272 

Meter-dials,  rouhd-reading  register  and 
straight-reading  register,  271 

Meter-record  book,  231 

Meter-testing  apparatus,  272 

Meter-tests,  card  for,  274 

Metered  water,  rates  for,  369 

Meters,  265  ff. ;  classes  of  •  oscillating, 
reciprocating,  rotary,  265 ;  points 


INDEX. 


425 


to  be  considered  in  selection  of, 
267 ;  maximum  capacity  of,  267 ; 
Union  rotary-piston,  266;  Crown, 
268;  Worthington  disk,  269; 
Empire,  270;  cost  of,  271;  ap- 
paratus for  testing,  272;  where 
placed,  274;  manhole  setting  for, 
275;  cost  of  setting,  276,  277; 
method  of  testing  accuracy  of,  278 ; 
reading  of,  279;  cost  of  maintain- 
ing, 279,  375;  cost  of  reading,  279; 
cost  of  repairs,  279;  for  waste 
water,  332,  333;  effect  of  use  of, 
on  consumption  of  water,  340 

Micro-organisms,  in  lakes  and  reser- 
voirs, 207,  311  ff. ;  table  of,  317; 
experiments  in  removing,  318;  in 
ground-waters,  319;  in  pipes,  319 

Mineral  matters,   10 

Mississippi  River,  113,  117,  124 

Missouri  River  water,  113,  117,  124, 
125,  140,  143,  148;  experiment  in 
drinking  when  treated  with  sul- 
phate of  alumina  solution,  151 

Missouri  River  sands,  analyses  of,  33 

Muddiness,  133 

Muscatine,  la.,  water-supply,  problems 
presented  for  solution,  23;  water- 
level  observation,  25;  ground- 
water  table  during  pump  test,  28; 
sand  and  gravel,  mechanical  anal- 
yses of,  30;  sands,  effective  size 
and  uniformity  coefficient  of,  38; 
conditions,  82 

Muscatine  Island,  geological  structure 
of,  22 

Natural  coagulation,  159 

New  Croton  dam,  216 

New  England  Water- works  Association, 

238,  239,  246,  381-384 
Nitrates,  3,  4,  322 
Nitrites,  3,  322 

Ohio  River,  suspended  matter  in,  124 
Open  well,  48  ff. 
Open-well  construction,  72 
Oscillating  meters,  265 
Overturning,  314 
Oxygen  consumed,  322 

Parallel  flow,  84 

Peoria,  111.,  breaks  in  service-pipes  of, 

345 
Per     capita     consumption,     metered, 

compared  with  schedule-rate,  342 
Percolating  capacity  of  soils,  43,  44 
Permanent  yielding  capacity,   factors 

for  the  determination  of,  41 
Piezometer   method  of  measurement, 

193 


Pig-lead,  cost  of,  247 

Pipe,  cement-lined  iron,  cost  of,  262, 
263;  lead,  cost  of,  263;  lead, 
weights  of,  263;  tin-lined  lead, 
254,  257,  264 

Pipe  connections,  details  of,  1 76 

Pipe-cutter,  Hall,  300 

Pipe -cutting  machine,  French,  300 

Pipe-derrick,  234 

Pipe  for  water-mains,  thickness  of,  238, 
357 

Pipe-jointer,  23.5 

Pipe-laying,  cost  of,  247 

Pipe-laying  tools,  237 

Pipe-line,  main,  232 

Pipe-scraper,  291 

Pipes,  care  of,  in  extending  water- 
works, 234-236;  cast-iron,  stand- 
ard thicknesses  and  weights  of, 
241;  cost  of,  248;  wrought-iron, 
254 ;  cracked,  304.  See  also  Pipe 

Pipes  and  special  castings,  general 
dimensions  of,  240 

Pitometer,  Cole-Flad,  334 

Pitometer  record,  335 

Pittings  at  joint  in  water-main,  346 

Planks,  curtain  of,  119 

Plans,  construction,  218 

Plans  and  records  of  maintenance  and 
operation,  218  ff. 

Plants,  average  cost  of,  401,  402,  407; 
cost  of  production  of  municipal  and 
private,  403 ;  earnings  of,  403 

Platting,  results  of,  35 

Plumbing  fixtures  and  water   waste, 

324 

Plunger-displacement  method  of  meas- 
urement, 193 

Plunger-packing,  fibrous,  196;  metal, 
196 

Plunger-pump,  196 

Polluting  matter,  6 ;  discharge  of,  311 

Pollution,  84 

Population,  water  consumption,  and 
receipts  for  water,  summarized 
and  averaged,  341 

Post  hydrants,  cost  of,  248 

Pounding,  cause  of,  281 

Precipitation,  measurement  of,  224 

Pressure,  stand-pipe,  for  domestic 
service,  197;  direct,  for  fire-ser- 
vice, 197 

Pressure-recording  gages,  229 

Private  waterworks  property,  no  spec- 
ulative value  in,  404 

Production,  cost  of,  403 

Proximity  to  desirable  locality  for 
water-supply  development,  83 ; 
danger  of  pollution,  84 

Pump-slippages  in  a  number  of  cities, 
282 


426 


INDEX. 


Pump-valves,  wear  and  tear  of,  195; 
size  and  lift  of,  195 

Pumping,  cost  of,  in  various  localities, 
283 

Purnping-engines,  183  ff . ;  high-pres- 
sure, 1 06;  at  Liberty,  Mo.,  109; 
"mechanical  efficiency"  applied 
to,  184;  economy  of,  184;  unit 
volume  of,  185;  steam  consump- 
tion and  coal  consumption,  186; 
station  duty  and  test  duty,  187; 
station  duties  from  various  types 
of,  191;  lowest-grade,  196;  com- 
pound condensing  duplex,  198; 
high-duty,  not  necessary  for  small 
towns,  201;  life  of,  201 

Pumping  machinery,  133 

Pumping-plant,  efficiency  of,  principal 
factor  in  determining,  282 

Pumping  records,  230 

Pumping-station  records,  method  of 
keeping,  188 

Pumping  tests,  38,  39 

Pumps,  slip  of,  192,  193 

Purification  of  water,  natural,  2 ;  sub- 
sidence, coagulation,  and  nitra- 
tion necessary  for,  182 

Purification  works.  See  Water-purifi- 
cation works 

Quality  of  water-supply,  maintenance 

of,  311 
Quindaro  settling-basin,  127 

Radial  flow,  law  of,  61 

Rainfall,  2;   pollution  of,  5 

Rain-gage,  standard,  of  Weather 
Bureau,  224 

Rate  assessment,  change  from  schedule 
to  meter  basis  of,  374 

Rate  of  flow  through  a  filter,  uniform, 
1 66 

Raw-water  basin,  127 

Reciprocating  meters,  265 

Record,  water-works  and  water-supply, 
42 

Record -books,  222 

Record  of  service,  223 

Record  plans,  219 

Recording  devices,  229 

Records,  construction,  221 ;  main-pipe, 
valve,  and  hydrant,  222;  main- 
tenance, 223 

Removal  of  iron,  85  ff. 

Repair  sleeves,  Kellogg,  303 

Repairing  steel  main,  method  of,  304 

Reports,  annual,  380  ff. 

Rerating  water  service,  418 

Reservoirs,  cleaned  and  uncleaned, 
analyses  of  water  from,  207;  im- 
pounding, capacity  of,  210 


Revenue  from  sale  of  water  service, 

distribution  of,  416,  417 
River  pollution,  source  of,  in  the  East, 

116;  in  the  Middle  West,  116 
River  valleys,   deposits  of  sand  and 

gravel  in,  19;  value  of,  as  sources 

of  water-supply,  19 
River- water  supply,  116;  treating  with 

lime-water,     153;     winter    treat- 
ment of,  156,  157 
Rivers,  self -purification  of,  157 
Rivers  Pollution  Commission  on  the 

Domestic  Water  Supplies  of  Great 

Britain,  9 

Rock  excavation,  cost  of,  247 
Rock  wells,  67,  68 
Rods,  steel,  105 
Rotary  meters,  265 
"Round  way"  type  of  cocks,  253 
Rules  and  regulations  governing  use  of 

water,  377  ff. 
Run-off,  underground,  42,  45 

St.  Louis,  results  of  sedimentation  at, 
125 

Sand,  grade  of,  32 ;  mechanical  analy- 
sis of ,  32;  water-bearing  capacity 
of,  38 

Sand  filters,  161 

Sand  filtration,  117 

Sand  grains,  relation  between  sieve 
number  and  effective  size  of,  35 

Sands  and  gravels,  in  river  valleys,  19; 
coefficient  of  porosity  of,  31 

Scrapers,  289,  290,  292 

Securities,  water-works,  interest  of, 
403 

Sediment,  remnant  of,  126;  in  river- 
water,  average  amount  of  (Merri- 
mac,  Hudson,  Allegheny,  Potomac, 
Ohio,  Mississippi  rivers),  169,  170 

.Sedimentation,  fill-and-draw  method 
of,  117,  118;  continuous  -  flow 
method,  117,  118;  natural  or 
plain,  123,  126,  127,  137;  with 
aid  of  coagulant,  123,  137  ff, ; 
slower  in  spring,  126;  natural,  «t-t 
an  effective  means  of  thorough 
clarification  of  muddy  river-water, 
127,  137;  unsatisfactory  results 
from  fill-and-draw  method,  142 

Self-purification  of  rivers,  157 

Service  application,  223 

Service-boxes,  259;  Buffalo,  260; 
Stacy,  260;  Chadbourne,  260; 
cost  of,  262 

Service-clamp,  Mueller,  250 

Service  connections,  249;  diagram 
of,  221;  location  of,  260,  307; 
outside  and  within  street  limits, 
367 


INDEX. 


427 


Service -meters.     See  Meters 

Service-pipes,  lead,  257,  258;  quantity 
of  water  contained  in,  259;  gal- 
vanized-iron,  cost  of,  262;  lead- 
and  tin-lined,  cost  of,  262;  dis- 
charge of,  263;  cement-lined,  F. 
F.  Forbes  on,  255;  of  Peoria,  111., 
345;  protection  of  those  beneath 
railway  tracks,  351 

Services,  thawing,  by  the  electric  cur- 
rent, 296 

Settling-basins,  for  clarifying  muddy 
water,  116,  117  ff. ;  methods  of 
operating,  117;  with  baffle-walls, 
119;  plans  of,  120  ff.;  of  Kansas 
City  (Mo.)  water-works,  124,  125, 
I33I  Quindaro,  127;  on  displace- 
ment plan,  operating,  129;  tem- 
perature of  water  in,  134;  deep, 
136;  figure  of,  137;  advantages 
of,  155;  when  an  inadequate 
safeguard,  157;  difficulties  in 
operation  of,  173;  capacity  of,  173; 
plan  of,  174 

Sewage  contamination,  311,  322 

Seyssel  mastic,  308 

Shallow  ground-water  supplies,  19 

Short-stroke,  defined,  197 

Sieve  number  and  effective  size  of  sand 
grains,  35 

Single-trolley  system,  injury  to  water- 
pipes  resulting  from  use  of,  350, 

35 * 

Sinking-fund,  table,  414,  415;  applica- 
tion of,  416;  annuities  to  a,  416 

Siphon  pipe,  54  ff.,  73  ff-,  81 

Siphons  connecting  wells,  54 ;  multiple, 

55 
Skeleton  plan  of  distribution  system, 

219 

Sleeves,  repair,  303 
Slope  to  produce  maximum  discharge, 

57 

Softening  of  water,  16 
Soils,  percolating  capacity  of,  43,  44 
Soils  and  sands,  absorbing  capacity  of, 

43 

Solder,  cost  of,  264 

Spillway,  216 

Stagnation,  314 

Stand-pipes,  care  of,  283 

Station  duty  of  pumping-machinery, 
diagram  of,  188;  table  of,  191 

Station  duty  vs.  test  duty  of  pumping- 
engine,  187 

Statistics,  general,  382 ;  pumping,  382 ; 
financial,  383 ;  of  consumption  of 
water,  384;  relating  to  distribu- 
tion system,  384 

im    consumption    in    pumping-en- 
gine,  1 86 


Steel  main,  method  of  repairing,  304 

Sterilization  of  water,  167 

Stock  account,  365 

Stop  and  waste  cocks,  252;  union- 
joint,  252;  inverted-key,  253; 
compression,  253;  location  of,  261 ; 
cost  of,  262 

Stop-cock  replacer,  Thomas-Nusser,  306 

Storage,  clear-water,  173 

Storage  reservoir,  reinforced-concrete, 
178;  water  from,  preferred  to 
that  taken  from  a  stream,  204; 
safeguards  against  epidemics,  205 ; 
condition  of  bottom  of,  205 

Storing  water-supplies,  i  ff. 

Strainers,  59  ff. ;  casing-tubes  for,  69  ff. 

Stratification,  tendency  to,  133,  135 

Streams,  dry- weather  flow  of,  41 

Subsidence,  natural,  123 

Subsiding-basin.     See  Settling-basin 

Suction-pipe,  73  ff. 

Sudbury  catchment  area,  yield  of, 
212-214 

Sulphate  of  alumina,  137  ff.,  152;   for 
clarification,     142;     consumption. 
of,    in    Kansas    City    subsiding 
basin,   147;    as  a  coagulant,   148 

Sulphate  of  copper,  as  an  algicide,  158; 
combined  with  sulphate-of-iron 
coagulant,  158 

Sulphate  of  iron,  152,  154;  as  a  coagu- 
lant, 148 

Sulphate  of  lime  and  magnesia,  139 

Supervision,  skilled,  159 

Supplies,  impounded,  204;  micro-or- 
ganisms in,  207;  high  tempera- 
ture of,  210;  capacity  of,  210 

Surface  currents,  to  avoid,  119,  136 

Surface-water,  filtered,  112;  impure, 
ground-water  more  desirable  than, 
113;  purification,  114 

Swamp  before  and  after  construction 
of  drains,  313,  3 15 

Swamp    drainage    for   watershed   im- 
provement, 312,  315 
Swinging  motion  of  water,  136 
Sylvester  process,  310 

Tapping-machine,  Hall,  249;    cost  of, 

262 

Taxes,  average,  403 
Temperature  observations,  134  ff. 
Thawing,    method   used   at    Holyoke, 

Mass. ,  295 ;  by  the  electric  current, 

295,  297 

Thawing-machine,  Burbank,  294 
Tools,  pipe-laying,  237 
Town,  proximity  of,  to  ground-water 

supply,  83 
Trench,  one,  for  both  water  and  sewer 

connections,  261 


428 


INDEX. 


Tubercules,  removal  of,  289 
Tubular  wells,  64,  79  ff.,  83 
Turbidity,  14;  observations,  133, 143  ff., 
169;  change  of ,  137;  limit  of ,  170 
Turbine-pumps,  high-lift,  200 

Underflow,  velocity  of,  to  get,  29,  30; 

volume  of,  41 
Underground  run-off,  42,  45 
Uniformity  coefficient,  33 
Unit  volume,  185 

Value,  on  what  it  depends,  393 

Valve,  main,  220;  position  of,  233; 
Chapman,  244;  Coffin,  244;  Lud- 
low,  245;  Eddy,  246;  adjustable- 
wedge,  243 ;  for  water-main,  cost 
of,  247;  care  of,  286 

Valve-boxes,  247 ;  cost  of,  248 ;  care  of, 
287 

Valve-location  book,  219 

Venturi  meter,  225,  226,  331,  334; 
meter  chart,  331 

Voltmeter  measurements,  347,  351 

Wash-water,  percentage  and  cost  of,  1 72 
Waste,  investigations  of,  330  ff. 
Waste  prevention,  338  ff. 
Waste-water  meter,  Deacon,  332,  333 
Water,  shallow -well,  6;  deep-ground, 
7;  ideal,  13;  softening  of,  16; 
flow  of,  through  sands  and  sand- 
stones, 31;  flow  of,  through  un- 
assorted sands,  formula  for,  36; 
actually  pumped,  48 ;  filtered  well, 
112;  swinging  motion  of,  136; 
clearest,  136.  137;  clarification  by 
sedimentation  and  coagulation, 
149;  sterilization  of ,  167;  color  of, 
effect  of  long  storage  upon,  205; 
in  Lake  Cochituate  and  Ashland 
reservoirs,  206-209 ;  weight  of  one 
cubic  foot  of,  273;  in  pond  or 
reservoir,  character  of,  313 ;  phys- 
ical and  microscopical  examina- 
tion of,  321 ;  chemical  analysis  of, 
322;  for  domestic  purposes,  325; 
metered  consumption  of,  326;  in 
tenement-houses,  327;  quantities 
required  by  a  community,  329; 
quantity  required  for  public  use, 
329;  discrepancy  between  water 
registered  by  meters  and  amount 
delivered  into  mains,  329;  receipts 
for,  341;  schedule-rate  consump- 
tion of,  342 ;  use  of,  rules  and 
regulations  governing,  377  ff. ;  re- 
garded as  a  commodity,  392 ;  as  a 
product  of  nature,  392 
Water-bearing  capacity  of  a  sand,  38 
Water-bearing  gravel,  depth  of,  51 


Water-level  observations  at  Musca- 
tine,  la.,  24,  25 

Water-meters,  ownership  of,  368;  cost 
of,  368;  cost  of  maintaining,  375; 
objections  to  use  of,  405 

Waterphone,  337,  338 

Water-pipes,  relocation  of  grade  of, 
301 

Water-pressure  governor,  197 

Waterproofing  of  walls  of  gate-cham- 
bers and  reservoir  linings,  309; 
Sylvester  process,  310 

Water-purification  works,  105,  114, 
121 ;  at  Richmond,  Mo.,  87  ff.,  91- 
104;  at  Liberty,  Mo.,  105  ff. ; 
hygienic  quality  of  water  from, 
112;  combining  natural  subsi- 
dence, coagulation,  and  mechanical 
filtration,  174 

Water  rates,  369  ff.,  392  ff. ;  schedule, 
fixed,  or  assessed,  369;  meter,  369; 
collected  in  advance,  372;  gradu- 
ated minimum,  375 

Water  service,  sale  of,  without  measure- 
ment, 393;  graded  tariff  of,  394; 
rerating,  418;  revenue  from  sale 
of,  416,  417 

Water-softening,  16 

Water-supplies,  developing,  improving, 
and  storing,  methods  and  princi- 
ples of,  i  ff. 

Water-supply,  of  Galveston,  7;  clear- 
ness of ,  14;  development,  75,  114; 
of  Bremen,  Germany,  168;  from 
flowing  streams,  317;  sanitary 
examination  of,  320 

Water-table,  limit  of  depression  of,  57 

Water  waste,  324;  plumbing  fixtures 
and,  324;  preventable,  325;  ball- 
cock  greatest  source  of,  330 

Water- works,  extensions  of,  232  ff. ; 
deterioration  of,  389;  deficit  in, 
395  >  private,  401,  402,  404; 
municipal,  402 

Water-works  force  account,  365 

Water-works    system,    benefits    from, 

37i 

Weir  method  of  measurement,  193 
Weirs,    118,    119,    149;    elevation  of, 

129  ff. ;  flow  of  water  over,  226 
Well,  deep,  water  from,  7  ff. ;    single 

open,  48 ;  substitute  for,  56 ;  close, 

72;  water,  filtered,  112 
Well-strainers,  59;  length  of,  65;  area 

of  openings,  66,  67 ;    form  of,  an 

important  consideration,  68  ff. 
Well  system,  layout  of,   83;    strainer 

capacity,  83;  pipe  resistance,  83 
Well  water,   from   deep  wells,    7    ff. ; 

filtered,  112 
Wells,  light,  300 


INDEX. 


429 


Weser,  water  of,  168;  United  States 
rivers  comparable  with,  169 

Wholesomeness  and  clearness,  15 

Winslow  electrical  indicating  and 
recording  apparatus,  229 

Winter  treatment  of  river-water,  156, 
157 


Wrought  iron,  pipes  of,  254 

Yarn,  cost  of,  247 
Yarning-iron,  237 
Yielding  capacity,  factors  for 

determination    of,    40,    41 ; 

manent,  of  sand-bed,  48 


the 
per- 


SHORT-TITLE     CATALOGUE 

OF  THE 

PUBLICATIONS 

OF 

JOHN   WILEY   &    SONS, 

NEW  YORK. 
LONDON:  CHAPMAN  &  HALL,  LIMITED. 


ARRANGED  UNDER  SUBJECTS. 


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Budd  and  Hansen's  American  Horticultural  Manual: 

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Sanderson's  Insects  Injurious  to  Staple  Crops i2mo,  i  50 

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Stockbridge's  Rocks  and  Soils 8vo,  2  50 

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1 


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Freitag's  Architectural  Engineering Svo,  3  50 

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French  and  Ives's  Stereotomy Svo,  2  50 

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Theatre  Fires  and  Panics i2mo,  i  50 

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Holly's  Carpenters'  and  Joiners'  Handbook iSmo,  75 

Johnson's  Statics  by  Algebraic  and  Graphic  Methods Svo,  2  oo 

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Merrill's  Stones  for  Building  and  Decoration Svo,  5  oo 

Non-metallic  Minerals:   Their  Occurrence  and  Uses Svo,  4  oo 

Monckton's  Stair-building 4to,  4  oo 

Patton's  Practical  Treatise  on  Foundations Svo,  5  oo 

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Richey's  Handbook  for  Superintendents  of  Construction i6mo,  mor.,  4  oo 

*              Building  Mechanics'  Ready  Reference  Book.     Carpenters'  and  Wood- 
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Snow's  Principal  Species  of  Wood Svo,  3  50 

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Towne's  Locks  and  Builders'  Hardware iSmo,  morocco,  3  oo 

Wait's  Engineering  and  Architectural  Jurisprudence Svo,  6  oo 

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Wood's  Rustless  Coatings:   Corrosion  and  Electrolysis  of  Iron  and  Steel.  .Svo,  4  oo 
Worcester  and  Atkinson's  Small  Hospitals,  Establishment  and  Maintenance, 
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i2mo,  i  25 

The  World's  Columbian  Exposition  of  1893 Large  4to,  i  oo 


ARMY  AND  NAVY. 

Bernadou's  Smokeless  Powder,  Nitro-cellulose,  and  the  Theory  of  the  Cellulose 

Molecule i2mo,  2  50 

Chase's  Screw  Propellers  and  Marine  Propulsion Svo,  3  oo 

Cloke's  Gunner's  Examiner 8vo,  i  50 

Craig's  Azimuth 4to,  3  50 

Crehore  and  Squier's  Polarizing  Photo-chronograph Svo,  3  oo 

*  Davis's  Elements  of  Law .Svo,  2  50 

*  Treatise  on  the  Military  Law  of  United  States Svo,  7  oo 

Sheep,  7  50 

De  Brack's  Cavalry  Outposts  Duties.     (Carr.) 24mo,  morocco,  2  oo 

Dietz's  Soldier's  First  Aid  Handbook i6mo,  morocco,  i  25 

*  Dudley's  Military  Law  and  the  Procedure  of  Courts-martial. .  .  Large  i2mo,  2  50 
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*  Dyer's  Handbook  of  Light  Artillery i2mo,  3  oo 

Eissler's  Modern  High  Explosives 8vo,  4  oo 

*  Fiebeger's  Text-book  on  Field  Fortification Small  Svo,  2  oo 

Hamilton's  The  Gunner's  Catechism iSmo,  i  oo 

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2 


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*  Ballistic  Tables 8vo,  i  50 

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Manual  for  Courts-martial i6mo,  morocco,  I  50 

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Powell's  Army  Officer's  Examiner i2mo,  4  oo 

Sharpe's  Art  of  Subsisting  Armies  in  War 1 8mo,  morocco,  i  50 

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Woodhull's  Notes  on  Military  Hygiene i6mo,  i  50 

Young's  Simple  Elements  of  Navigation i6mo,  morocco,  2  oo 

ASSAYING. 

Fletcher's  Practical  Instructions  in  Quantitative  Assaying  with  the  Blowpipe. 

i2mo,  morocco,  i  50 

Furman's  Manual  of  Practical  Assaying 8vo,  3  oo 

Lodge's  Notes  on  Assaying  and  Metallurgical  Laboratory  Experiments.  .  .  .8vo,  3  oo 

Low's  Technical  Methods  of  Ore  Analysis 8vo,  3  oo 

Miller's  Manual  of  Assaying I2mo,  i  oo 

Cyanide  Process i2mo,  i  oo 

Minet's  Production  of  Aluminum  and  its  Industrial  Use.     (Waldo.) i2mo,  2  50 

O'Driscoll's  Notes  on  the  Treatment  of  Gold  Ores 8vo,  2  oo 

Ricketts  and  Miller's  Notes  on  Assaying 8vo,  3  oo 

Robine  and  Lenglen's  Cyanide  Industry.     (Le  Clerc.) 8vo,  4  oo 

Ulke's  Modern  Electrolytic  Copper  Refining 8vo,  3  oo 

Wilson's  Cyanide  Processes I2mo,  i  50 

Chlorination  Process I2mo,  i  50 

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Comstock's  Field  Astronomy  for  Engineers 8vo,  2  50 

Craig's  Azimuth 4to,  3  50 

Crandall's  Text-book  on  Geodesy  and  Least  Squares 8vo,  3  oo 

Doolittle's  Treatise  on  Practical  Astronomy 8vo,  4  oo 

Gore's  Elements  of  Geodesy 8vo,  2  50 

Hayford's  Text-book  of  Geodetic  Astronomy 8vo,  3  oo 

Merriman's  Elements  of  Precise  Surveying  and  Geodesy 8vo,  2  50 

*  Michie  and  Harlow's  Practical  Astronomy.  .  .* 8vo,  3  oo 

*  White's  Elements  of  Theoretical  and  Descriptive  Astronomy i2mo  oo 

BOTANY. 

Davenport's  Statistical  Me'.hDds,  with  Special  Reference  to  Biological  Variation. 

i6mo,  morocco,  i  25 

Thome*  and  Bennett's  Structural  and  Physiological  Botany i6mo,  2  25 

Westermaier's  Compendium  of  General  Botany.     (Schneider.) 8vo,  2  oo 

3 


CHEMISTRY. 

*  Abegg's  Theory  of  Electrolytic  Dissociation.    (Von  Ende.) i2mo,  i  25 

Adriance's  Laboratory  Calculations  and  Specific  Gravity  Tables i2mo.  i  25 

Alexeyeff's  General  Principles  of  Organic  Synthesis.     (Matthews.) 8vo.  3  oo 

Allen's  Tables  for  Iron  Analysis 8vo,  3  oo 

Arnold's  Compendium  of  Chemistry.     (Mandel.) Small  8vo,  3  50 

Austen's  Notes  for  Chemical  Students i2mo,  i  50 

Bernadou's  Smokeless  Powder. — Nitro-cellulose,  and  Theory  of  the  Cellulose 

Molecule i2mo,  2  50 

*  Browning's  Introduction  to  the  Rarer  Elements 8vo,  i  50 

Brush  and  Penfield's  Manual  of  Determinative  Mineralogy 8vo,  4  oo 

*  Claassen's  Beet-sugar  Manufacture.     (Hall  and  Rolfe.) 8vo,  3  oo 

Classen's  Quantitative  Chemical  Analysis  by  Electrolysis.    (Boltwood.).  .8vo,  3  oo 

Conn's  Indicators  and  Test-papers i2mo,  2  oo 

Tests  and  Reagents 8vo,  3  oo 

Crafts's  Short  Course  in  Qualitative  Chemical  Analysis.   (Schaeffer.).  .  .  i2mo,  i  50 

*  Danneel's  Electrochemistry.     (Merriam.) i2mo,  i  25 

Dolezalek's  Theory  of  the   Lead  Accumulator   (Storage  Battery).        (Von 

Ende.) i2mo,  2  50 

Drechsel's  Chemical  Reactions.     (Merrill.) i2mo,  i  25 

Duhem's  Thermodynamics  and  Chemistry.     (Burgess.) 8vo,  4  oo 

Eissler's  Modern  High  Explosives 8vo,  4  oo 

Effront's  Enzymes  and  their  Applications.     (Prescott.) 8vo,  3  oo 

Erdmann's  Introduction  to  Chemical  Preparations.     (Dunlap.) i2mo,  i  25 

Fletcher's  Practical  Instructions  in  Quantitative  Assaying  with  the  Blowpipe. 

i2mo,  morocco,  i  50 

Fowler's  Sewage  Works  Analyses i2mo,  2  oo 

Fresenius's  Manual  of  Qualitative  Chemical  Analysis.     (Wells.) 8vo,  5  oo 

Manual  of  Qualitative  Chemical  Analysis.  Part  I.  Descriptive.  (Wells.)  8vo,  3  oo 

Quantitative  Chemical  Analysis.    (Cohn.)    2  vols 8vo,  12  50 

Fuertes's  Water  and  Public  Health I2mo,  i  50 

Furman's  Manual  of  Practical  Assaying 8vo,  3  oo 

*  Getman's  Exercises  in  Physical  Chemistry I2mo,  2  oo 

Gill's  Gas  and  Fuel  Analysis  for  Engineers i2mo,  i  25 

*  Gooch  and  Browning's  Outlines  of  Qualitative  Chemical  Analysis.  Small  8vo,  i  25 

Grotenfelt's  Principles  of  Modern  Dairy  Practice.     (Woll.). i2mo,  2  oo 

Groth's  Introduction  to  Chemical  Crystallography  (Marshall) i2mo,  i  25 

Hammarsten's  Text-book  of  Physiological  Chemistry.     (Mandel.) 8vo,  4  oo 

Helm's  Principles  of  Mathematical  Chemistry.     (Morgan.) i2mo,  i  50 

Boring's  Ready  Reference  Tables  (Conversion  Factors) i6mo,  morocco,  2  50 

Herrick's  Denatured  or  Industrial  Alcohol , Fvo,  4  oo 

Hind's  Inorganic  Chemistry 8vo,  3  oo 

*  Laboratory  Manual  for  Students I2mo,  i  oo 

Holleman's  Text-book  of  Inorganic  Chemistry.     (Cooper.) 8vo,  2  50 

Text-book  of  Organic  Chemistry.     (Walker  and  Mott.) 8vo,  2  50 

*  Laboratory  Manual  of  Organic  Chemistry.     (Walker.) i2mo,  i  oo 

Hopkins's  Oil-chemists'  Handbook 8vo,  3  oo 

Iddings's  Rock  Minerals 8vo,  5  oo 

Jackson's  Directions  for  Laboratory  Work  in  Physiological  Chemistry.  .8vo,  i  25 

Keep's  Cast  Iron .• 8vo,  2  50 

Ladd's  Manual  of  Quantitative  Chemical  Analysis i2mo,  i  oo 

Landauer's  Spectrum  Analysis.     (Tingle.) 8vo,  3  oo 

*  Langworthy  and  Austen.        The   Occurrence   of  Aluminium  in  Vegetable 

Products,  Animal  Products,  and  Natural  Waters 8vo,  2  oo 

Lassar-Cohn's  Application  of  Some  General  Reactions  to  Investigations  in 

Organic  Chemistry.  (Tingle.) I2mo,  i  oo 

Leach's  The  Inspection  and  Analysis  of  Food  with  Special  Reference  to  State 

Control 8vo,  7  50 

Lob's  Electrochemistry  of  Organic  Compounds.  (Lorenz.) 8vo,  3  oo 

4 


Lodge's  Notes  on  Assaying  and  Metallurgical  Laboratory  Experiments. ..  .8vo,  3  oo 

Low's  Technical  Method  of  Ore  Analysis 8vo,  3  oo 

Lunge's  Techno-chemical  Analysis.     (Cohn.) I2mo  i  oo 

*  McKay  and  Larsen's  Principles  and  Practice  of  Butter-making 8vo,  i  50 

Mandel's  Handbook  for  Bio-chemical  Laboratory i2mo,  i  50^ 

*  Martin's  Laboratory  Guide  to  Qualitative  Analysis  with  the  Blowpipe .  .  i2mo,  60- 
Mason's  Water-supply.     (Considered  Principally  from  a  Sanitary  Standpoint.) 

3d  Edition,  Rewritten 8vo,  4  oo~ 

Examination  of  Water.     (Chemical  and  Bacteriological. ) i2mo,  i  25 

Matthew's  The  Textile  Fibres.    2d  Edition,  Rewritten 8vo,  400 

Meyer's  Determination  of  Radicles  in  Carbon  Compounds.     (Tingle.).  .i2mo,  i  oo' 

Miller's  Manual  of  Assaying i2mo,  i  ocr 

Cyanide  Process i2mo,  i  oo 

Minet's  Production  of  Aluminum  and  its  Industrial  Use.     (Waldo.).  .  .  .  i2mo,  2  50 

Mixter's  Elementary  Text-book  of  Chemistry I2mo,  I  50 

Morgan's  An  Outline  of  the  Theory  of  Solutions  and  its  Results i2mo,  i  oo 

Elements  of  Physical  Chemistry I2mo,  3  oo 

*  Physical  Chemistry  for  Electrical  Engineers i2mo,  S^oo 

Morse's  Calculations  used  in  Cane-sugar  Factories i6mo,  morocco,  i  50 

*  Muir's  History  of  Chemical  Theories  and  Laws 8vo,  4  oo 

Mulliken's  General  Method  for  the  Identification  of  Pure  Organic  Compounds. 

Vol.  I Large  8vo,  5  oo 

O'Brine's  Laboratory  Guide  in  Chemical  Analysis 8vo,  oo 

O'Driscoll's  Notes  on  the  Treatment  of  Gold  Ores , 8vo,  oo 

Ostwald's  Conversations  on  Chemistry.     Part  One.     (Ramsey.) I2mo,  50 

"           "             Part  Two.     (TurnbulL) I2mo,  oo 

*  Pauli's  Physical  Chemistry  in  the  Service  of  Medicine.     (Fischer.) ....  i2mo,  25 

*  Penfield's  Notes  on  Determinative  Mineralogy  and  Record  of  Mineral  Tests. 

8vo,  paper,  50 

Pictet's  The  Alkaloids  and  their  Chemical  Constitution.     (Biddle.) 8vo,  5  oo 

Pinner's  Introduction  to  Organic  Chemistry.     (Austen.) I2mo.  i  50 

Poole's  Calorific  Power  of  Fuels 8vo,  3  oo 

Prescott  and  Winslow's  Elements  of  Water  Bacteriology,  with  Special  Refer- 
ence to  Sanitary  Water  Analysis I2mo,  I  25 

*  Reisig's  Guide  to  Piece-dyeing 8vo,  25  oo 

Richards  and  Woodman's  Air,  Water,  and  Food  from  a  Sanitary  Standpoint..8vo,  2  oo 
Ricketts  and  Russell's  Skeleton  Notes  upon  Inorganic   Chemistry.     (Part  I. 

Non-metallic  Elements.)    8vo,  morocco,  75 

Ricketts  and  Miller's  Notes  on  Assaying 8vo,  3  oo 

Rideal's  Sewage  and  the  Bacterial  Purification  of  Sewage 8vo,  4  oo 

Disinfection  and  the  Preservation  of  Food 8vo,  4  oo 

Riggs's  Elementary  Manual  for  the  Chemical  Laboratory 8vo,  i  25 

Robine  and  Lenglen's  Cyanide  Industry.     (Le  Clerc.) 8vo,  4  oo 

Ruddiman's  Incompatibilities  in  Prescriptions 8vo,  2  oo 

*  Whys  in  Pharmacy  . I2mo,  i  oo 

Sabin's  Industrial  and  Artistic  Technology  of  Paints  and  Varnish 8vo,  3  oo 

Salkowski's  Physiological  and  Pathological  Chemistry.     (Orndorff.) 8vo,  2  50 

Schimpf's  Text-book  of  Volumetric  Analysis I2mo,  2  50 

Essentials  of  Volumetric  Analysis I2mo,  i  25 

*  Qualitative  Chemical  Analysis 8vo,  i   25 

Smith's  Lecture  Notes  on  Chemistry  for  Dental  Students 8vo,  2  50 

Spencer's  Handbook  for  Chemists  of  Beet-sugar  Houses i6mo,  morocco,  3  oo 

Handbook  for  Cane  Sugar  Manufacturers i6mo,  morocco,  3  oo 

Stockbridge's  Rocks  and  Soils 8vo,  2  50 

*  Tollman's  Elementary  Lessons  in  Heat 8vo,  i  50 

*  Descriptive  General  Chemistry 8vo,  3  oo 

Treadwell's  Qualitative  Analysis.     (Hall.) 8vo,  3  oo 

Quantitative  Analysis.     (Hall.) 8vo,  4  oo 

Turneaure  and  Russell's  Public  Water-supplies 8vo,  5  oo. 

5 


Van  Deventer's  Physical  Chemistry  for  Beginners.     (Boltwood.)  ..... .i2mo,  i  50 

*  Walke's  Lectures  on  Explosives 8vo,  4  oo 

Ware's  Beet-sugar  Manufacture  and  Refining.     Vol.  I Small  8vo,  4  oo 

Vol.11 SmallSvo,  500 

Washington's  Manual  of  the  Chemical  Analysis  of  Rocks. . 8vo,  2  oo 

Weaver's  Military  Explosives 8vo,  3  oo 

Wehrenfennig's  Analysis  and  Softening  of  Boiler  Feed- Water 8vo,  4  oo 

Wells's  Laboratory  Guide  in  Qualitative  Chemical  Analysis 8vo,  i  50 

Short  Course  in  Inorganic  Qualitative  Chemical  Analysis  for  Engineering 

Students 121110,  i  50 

Text-book  of  Chemical  Arithmetic i2mo,  i  25 

Whipple's  Microscopy  of  Drinking-water 8vo,  3  50 

Wilson's  Cyanide  Processes I2mo,  i  50 

Chlorination  Process i2rno,  i  50 

Winton's  Microscopy  of  Vegetable  Foods 8vo,  7  50 

Wulling's    Elementary    Course    in  Inorganic,  Pharmaceutical,  and  Medical 

Chemistry I2mo,  2  oo 


CIVIL  ENGINEERING. 

BRIDGES    AND    ROOFS,       HYDRAULICS.       MATERIALS   OF   ENGINEERING. 
RAILWAY  ENGINEERING. 

Baker's  Engineers'  Surveying  Instruments i2mo,  3  oo 

Bixby's  Graphical  Computing  Table Paper  19^X24!  inches.  25 

Breed  and  Hosmer's  Principles  and  Practice  of  Surveying 8vo,  3  oo 

*  Burr's  Ancient  and  Modern  Engineering  and  the  Isthmian  Canal 8vo,  3  50 

Comstock's  Field  Astronomy  for  Engineers 8vo,  2  50 

Crandall's  Text-book  on  Geodesy  and  Least  Squares 8vo,  3  oo 

Davis's  Elevation  and  Stadia  Tables 8vo,  i  oo 

Elliott's  Engineering  for  Land  Drainage i2mo,  i  50 

Practical  Farm  Drainage i2mo,  i  oo 

*Fiebeger's  Treatise  on  Civil  Engineering 8vo,  5  oo 

Flemer's  Phototopographic  Methods  and  Instruments 8vo,  5  oo 

Folwell's  Sewerage.     (Designing  and  Maintenance.) 8vo,  3  oo 

Freitag's  Architectural  Engineering.     2d  Edition,  Rewritten 8vo,  3  So 

French  and  Ives's  Stereotomy 8vo,  2  50 

Goodhue's  Municipal  Improvements i2mo,  i  50 

Gore's  Elements  of  Geodesy 8vo,  2  50 

Hayford's  Text-book  of  Geodetic  Astronomy 8vo,  3  oo 

Bering's  Ready  Reference  Tables  (Conversion  Factors) i6mo,  morocco,  2  50 

Howe's  Retaining  Walls  for  Earth i2mo,  i  25 

*  Ives's  Adjustments  of  the  Engineer's  Transit  and  Level i6mo,  Bds.  25 

Ives  and  Hilts's  Problems  in  Surveying i6mo,  morocco,  i  50 

Johnson's  (J.  B.)  Theory  and  Practice  of  Surveying Small  8vo,  4  oo 

Johnson's  (L.  J.)  Statics  by  Algebraic  and  Graphic  Methods 8vo,  2  oo 

Laplace's  Philosophical  Essay  on  Probabilities.    (Truscott  and  Emory.).  i2mo,  2  oo 

Mahan's  Treatise  on  Civil  Engineering.     (1873.)     (Wood.) 8vo,  5  oo 

*  Descriptive  Geometry 8vo,  i  50 

Merriman's  Elements  of  Precise  Surveying  and  Geodesy 8vo,  2  50 

Merriman  and  Brooks's  Handbook  for  Surveyors i6mo,  morocco,  2  oo 

Nugent's  Plane  Surveying 8vo,  3  50 

Ogden's  Sewer  Design i2mo,  2  oo 

Parsons's  Disposal  of  Municipal  Refuse 8vo,  2  oo 

Patton's  Treatise  on  Civil  Engineering 8vo  half  leather,  7  50 

Reed's  Topographical  Drawing  and  Sketching 4to,  5  oo 

Rideal's  Sewage  and  the  Bacterial  Purification  of  Sewage 8vo,  4  oo 

Siebert  and  Biggin's  Modern  Stone-cutting  and  Masonry 8vo,  i  50 

6 


Smith's  Manual  01  Topographical  Drawing.     (McMillan.) 8vo,  2  50 

Sondericker's  Graphic  Statics,  with  Applications  to  Trusses,  Beams,  and  Arches. 

8vo,  2  oo 

Taylor  and  Thompson's  Treatise  on  Concrete,  Plain  and  Reinforced 8vo,  5  oo 

*  Trautwine's  Civil  Engineer's  Pocket-book i6mo,  morocco,  5  oo 

Venable's  Garbage  Crematories  in  America 8vo,  2  oo 

Wait's  Engineering  and  Architectural  Jurisprudence 8vo  6  oo 

Sheep,  6  50 

Law  of  Operations  Preliminary  to  Construction  in  Engineering  and  Archi- 
tecture  8vo,  5  oo 

Sheep,  5  50 

Law  of  Contracts 8vo,  3  oo 

Warren's  Stereotomy — Problems  in  Stone-cutting 8vo,  2  50 

Webb's  Problems  in  the  Use  and  Adjustment  of  Engineering  Instruments. 

i6mo,  morocco,  i  .25 

Wilson's  Topographic  Surveying 8vo,  3  50 


BRIDGES  AND  ROOFS. 

Boiler's  Practical  Treatise  on  the  Construction  of  Iron  Highway  Bridges.  .8vo,  2  oo 

*       Thames  River  Bridge 4to,  paper,  5  oo 

Burr's  Course  on  the  Stresses  in  Bridges  and  Roof  Trusses,  Arched  Ribs,  and 

Suspension  Bridges 8vo*  3  50 

Burr  and  Falk's  Influence  Lines  for  Bridge  and  Roof  Computations 8vo,  3  oo 

Design  and  Construction  of  Metallic  Bridges 8vo  5  oo 

Du  Bois's  Mechanics  of  Engineering.     Vol.  II Small  4to,  10  oo 

Foster's  Treatise  on  Wooden  Trestle  Bridges. . 4to,  5  oo 

Fowler's  Ordinary  Foundations 8vo,  3  50 

Greene's  Roof  Trusses 8vo,  i  25 

Bridge  Trusses 8vo,  2  50 

Arches  in  Wood,  Iron,  and  Stone 8vo  2  50 

Howe's  Treatise  on  Arches 8vo,  4  oo 

Design  of  Simple  Roof- trusses  in  Wood  and  Steel , 8vo,  2  oo 

Symmetrical  Masonry  Arches 8vo,  2  50 

Johnson,  Bryan,  and  Turneaure's  Theory  and  Practice  in  the  Designing  of 

Modern  Framed  Structures Small  4to,  10  oo 

Merrimin  and  Jacoby's  Text-book  on  Roofs  and  Bridges : 

Fori  L    Stresses  in  Simple  Trusses 8vo,  2  50 

Part  JL    Graphic  Statics 8vo,  2  50 

Fart  ffl.  Bridge  Design 8vo,  2  50 

Part  TV.   Higher  Structures • 8vo,  2  50 

Morison's  Memphis  Bridge 4to,  10  oo 

Waddell's  De  Pontibus,  a  Pocket-book  for  Bridge  Engineers.  . i6mo,  morocco,  2  oo 

*  Specifications  for  Steel  Bridges i2mo,  50 

Wright's  Designing  of  Draw-spans.     Two  parts  in  one  volume 8vo,  3  5<> 

HYDRAULICS. 

Barnes's  Ice  Formation 8vo»  3  oo 

Bazin's  Experiments  upon  the  Contraction  of  the  Liquid  Vein  Issuing  from 

an  Orifice.     (Trautwine.) 8vo-  2  °° 

Bovey's  Treatise  on  Hydraulics 8vo»  5  o 

Church's  Mechanics  of  Engineering 8vo,  6 

Diagrams  of  Mean  Velocity  of  Water  in  Open  Channels paper,  i  5° 

Hydraulic  Motors 8vo»  2  °° 

Coffin's  Graphical  Solution  of  Hydrr.ulic  Problems i6mo,  morocco,  2 

Flather's  Dynamometers,  and  the  Measurement  of  Power xamo,  3  oo 

7 


FolwelTs  Water-supply  Engineering 8vo,  4  oo 

FrizelTs  Water-power 8vo,  5  oo 

Fuertes's  Water  and  Public  Health i2mo,  i  50 

Water-filtration  Works. i2mo,  2  50 

Ganguillet  and  Kutter's  General  Formula  for  the  Uniform  Flow  of  Water  in 

Rivers  and  Other  Channels.     (Bering  and  Trautwine.) 8vo,  4  oo 

Hazen's  Filtration  of  Public  Water-supply 8vo,  3  oo 

Hazlehurst's  Towers  and  Tanks  for  Water-works 8vo,  2  50 

Herschel's  115  Experiments  on  the  Carrying  Capacity  of  Large,  Riveted,  Metal 

Conduits 8vo,  2  oo 

Mason's  Water-supply.     (Considered  Principally  from  a  Sanitary  Standpoint.) 

8vo,  4  oo 

Merriman's  Treatise  on  Hydraulics 8vo,  5  oo 

*  Michie's  Elements  of  Analytical  Mechanics 8vo,  4  oo 

Schuyler's   Reservoirs   for  Irrigation,   Water-power,   and   Domestic   Water- 
supply Large  8vo,  5  oo 

*  Thomas  and  Watt's  Improvement  of  Rivers 4to,  6  oo 

Turneaure  and  Russell's  Public  Water-supplies 8vo,  5  oo 

Wegmann's  Design  and  Construction  of  Dams 4to,  5  oo 

Water-supply  of  the  City  of  New  York  from  1658  to  1895 4to,  10  oo 

Whipple's  Value  of  Pure  Water Large  i2mo,  i  oo 

Williams  and  Hazen's  Hydraulic  Tables 8vo,  i  50 

Wilson's  Irrigation  Engineering Small  8vo,  4  oo 

Wolff's  Windmill  as  a  Prime  Mover 8vo,  3  oo 

Wood's  Turbines 8vo,  2  50 

Elements  of  Analytical  Mechanics . .  .8vo,  3  oo 


MATERIALS  OF  ENGINEERING. 

Baker's  Treatise  on  Masonry  Construction 8vo,  5  oo 

Roads  and  Pavements 8vo,  5  oo 

Black's  United  States  Public  Works Oblong  4to,  5  oo 

*  Bovey's  Strength  of  Materials  and  Theory  of  Structures 8vo,  7  50 

Burr's  Elasticity  and  Resistance  of  the  Materials  of  Engineering 8vo,  7  50 

Byrne's  Highway  Construction 8vo,  5  oo 

Inspection  of  the  Materials  and  Workmanship  Employed  in  Construction. 

i6mo,  3  oo 

Church's  Mechanics  of  Engineering 8vo,  6  oo 

Du  Bois's  Mechanics-of  Engineering.     Vol.  I. Small  4to,  7  50 

*Eckel's  Cements,  Limes,  and  Plasters 8vo,  6  oo 

Johnson's  Materials  of  Construction Large  8vo,  6  oo 

Fowler's  Ordinary  Foundations 8vo,  3  50 

Graves's  Forest  Mensuration 8vo,  4  oo 

*  Greene's  Structural  Mechanics 8vo,  2  50 

Keep's  Cast  Iron 8vo,  2  50 

Lanza's  Applied  Mechanics 8vo,  7  50 

Marten's  Handbook  on  Testing  Materials.     (Henning.)     2  vols 8vo,  7  50 

Maurer's  Technical  Mechanics 8vo,  4  oo 

Merrill's  Stones  for  Building  and  Decoration 8vo,  5  oo 

Merriman's  Mechanics  of  Materials 8vo,  5  oo 

*  Strength  of  Materials i2mo,  i  oo 

Metcalf's  Steel.     A  Manual  for  Steel-users i2mo,  2  oo 

Patton's  Practical  Treatise  on  Foundations 8vo,  5  oo 

Richardson's  Modern  Asphalt  Pavements 8vo,  3  oo 

Richey's  Handbook  for  Superintendents  of  Construction i6mo,  mor.,  4  oo 

*  Ries's  Clays:  Their  Occurrence,  Properties,  and  Uses 8vo,  5  oo 

Rockwell's  Roads  and  Pavements  in  France i2mo,  i  25 

8 


Sabin's  Industrial  and  Artistic  Technology  of  Paints  acd  Varnish 8vo,  3  oo 

*Schwarz's  Longleaf  Pine  in  Virgin  Forest  .. i«no,  i  25 

Smith's  Materials  of  Machines izmo,  i  oo 

Snow's  Principal  Species  of  Wood 8vo,  3  50 

Spalding's  Hydraulic  Cement izmo,  2  oo 

Text-book  on  Roads  and  Pavements I2mo,  2  oo 

Taylor  and  Thompson's  Treatise  on  Concrete,  Plain  and  Reinforced 8vo,  5  oo 

Thurston's  Materials  of  Engineering.     3  Parts 8vo,  8  oo 

Part  I.     Non-metallic  Materials  of  Engineering  and  Metallurgy 8vo,  2  oo 

Part  n.     Iron  and  SteeL 8vo,  3  50 

Part  in.     A  Treatise  on  Brasses,  Bronzes,  and  Other  Alloys  and  their 

Constituents 8vo,  2  50 

Tillson's  Street  Pavements  and  Paving  Materials 8vo,  4  oo 

WaddelPs  De  Pontibus.    (A  Pocket-book  for  Bridge  Engineers.).  .  i6mo,  mor.,  2  oo 

*         Specifications  for  Steel  Bridges i2mo,  50 

Wood's  (De  V.)  Treatise  on  the  Resistance  of  Materials,  and  an  Appendix  on 

the  Preservation  of  Timber 8vo,  2  oo 

Wood's  (De  V.)  Elements  of  Analytical  Mechanics 8vo,  3  oo 

Wood's  (M.  P.)  Rustless  Coatings:    Corrosion  and  Electrolysis  of  Iron  and 

SteeL 8vo,  4  oo 


RAILWAY  ENGINEERING. 

Andrew's  Handbook  for  Street  Railway  Engineers 3x5  inches,  morocco,  I  25 

Berg's  Buildings  and  Structures  of  American  Railroads 4to,  5  oo 

Brook's  Handbook  of  Street  Railroad  Location. i6mo,  morocco,  I  50 

Butt's  Civil  Engineer's  Field-book i6mo,  morocco,  2  50 

Crandall's  Transition  Curve i6mo,  morocco,  i  50 

Railway  and  Other  Earthwork  Tables 8vo,  I  50 

Dawson's  "Engineering"  and  Electric  Traction  Pocket-book.  .  i6mo,  morocco,  5  oo 

Dredge's  History  of  the  Pennsylvania  Railroad:   (1879) Paper,  5  oo 

Fisher's  Table  of  Cubic  Yards Cardboard,  25 

Godwin's  Railroad  Engineers'  Field-book  and  Explorers'  Guide.  .  .  i6mo,  mor.,  2  50 
Hudson's  Tables  for  Calculating  the  Cubic  Contents  of  Excavations  and  Em- 
bankments  8vo,  i  oo 

Molitor  and  Beard's  Manual  for  Resident  Engineers i6mo,  i  oo 

Nagle's  Field  Manual  for  Railroad  Engineers i6mo,  morocco,  3  oo 

Philbrick's  Field  Manual  for  Engineers i6mo,  morocco,  3  oo 

Searles's  Field  Engineering i6mo,  morocco,  3  oo 

Railroad  SpiraL i6mo,  morocco,  i  50 

Taylor's  Prismoidal  Formulas  and  Earthwork 8vo,  i  50 

*  Trautwine's  Method  of  Calculating  the  Cube  Contents  of  Excavations  and 

Embankments  by  the  Aid  of  Diagrams 8vo,  2  oo 

The  Field  Practice  of  Laying  Out  Circular  Curves  for  Railroads. 

i2mo,  morocco,  2  50 

Cross-section  Sheet Paper,  25 

Webb's  Railroad  Construction i6mo,  morocco,  5  oo 

Economics  of  Railroad  Construction Large  i2mo,  2  50 

Wellington's  Economic  Theory  of  the  Location  of  Railways Small  8vo,  5  oo 


DRAWING. 

Barr's  Kinematics  of  Machinery 8vo,  2  50 

*  Bartlett's  Mechanical  Drawing 8vo,  3  oo 

*  "                    "                    "        Abridged  Ed 8vo,  150 

Coolidge's  Manual  of  Drawing 8vo,  paper,  i  oo 

9 


Coolidge  and  Freeman's  Elements  of  General  Drafting  for  Mechanical  Engi- 
neers  Obkmg  4to,  2  50 

Durley's  Kinematics  of  Machines 8vo,  4  oo 

Emch's  Introduction  to  Projective  Geometry  and  its  Applications 8vo,  2  50 

Hill's  Text-book  on  Shades  and  Shadows,  and  Perspective SYO,  2  oo 

Jamison's  Elements  of  Mechanical  Drawing 8vo,  2  50 

Advanced  Mechanical  Drawing 8vo,  2  oo 

Jones's  Machine  Design: 

Part  I.     Kinematics  of  Machinery 8vo,  i  50 

Part  II.     Form,  Strength,  and  Proportions  of  Parts 8vo,  3  oo 

MacCord's  Elements  of  Descriptive  Geometry 8vo,  3  oo 

Kinematics ;   or,  Practical  Mechanism 8vo,  5  oo 

Mechanical  Drawing 4to,  4  oo 

Velocity  Diagrams 8vo,  i  50 

MacLeod's  Descriptive  Geometry Small  8vo,  i  50 

*  Mahan's  Descriptive  Geometry  and  Stone-cutting: 8vo,  i  50 

Industrial  Drawing.  (Thompson.) 8vo,  3  50 

Moyer's  Descriptive  Geometry 8vo,  2  oo 

Reed's  Topographical  Drawing  and  Sketching 4to,  5  oo 

Reid's  Course  in  Mechanical  Drawing 8vo,  2  oo 

Text-book  of  Mechanical  Drawing  and  Elementary  Machine  Design. 8vo,  3  oo 

Robinson's  Principles  of  Mechanism 8vo,  3  oo 

Schwamb  and  Merrill's  Elements  of  Mechanism 8vo,  3  oo 

Smith's  (R.  S.)  Manual  of  Topographical  Drawing.  (McMillan.) 8vo,  2  50 

Smith  (A.  W.)  and  Marx's  Machine  Design 8vo,  3  oo 

*  Titsworth's  Elements  of  Mechanical  Drawing Oblong  8vo,  i  25 

Warren's  Elements  of  Plane  and  Solid  Free-hand  Geometrical  Drawing.  i2mo,  i  oo 

Drafting  Instruments  and  Operations i2mo,  i   25 

Manual  of  Elementary  Projection  Drawing i2mo,  i  50 

Manual  of  Elementary  Problems  in  the  Linear  Perspective  of  Form  and 

Shadow i2tno,  i  oo 

Plane  Problems  in  Elementary  Geometry i2mo,  i  25 

Primary  Geometry. I2mo,  75 

Elements  of  Descriptive  Geometry,  Shadows,  and  Perspective 8vo,  3  50 

General  Problems  of  Shades  and  Shadows 8vo,  3  oo 

Elements  of  Machine  Construction  and  Drawing 8vo,  7  50 

Problems,  Theorems,  and  Examples  in  Descriptive  Geometry 8vo,  2  50 

Weisbach's    Kinematics    and    Power    of    Transmission.        (Hermann    and 

Klein.) 8vo,  5  oo 

Whelpley's  Practical  Instruction  in  the  Art  of  Letter  Engraving.  .....  .i2mo,  2  oo 

Wilson's  (H.  M.)  Topographic  Surveying 8vo,  3  50 

Wilson's  (V.  T.)  Free-hand  Perspective 8vof  2  50 

Wilson's  (V.  T.)  Free-hand  Lettering 8vo,  i  oo 

Woolf's  Elementary  Course  in  Descriptive  Geometry Large  8vo,  3  oo 


ELECTRICITY  AND  PHYSICS. 

*  Abegg's  Theory  of  Electrolytic  Dissociation.     (Von  Ende.) 12010,  i   25 

Anthony  and  Brackett's  Text-book  of  Physics.     (Magie.) Small  8vo  3  oo 

Anthony's  Lecture-notes  on  the  Theory  of  Electrical  Measurements.  .  .  .  12 mo,  i  oo 

Benjamin's  History  of  Electricity 8vo,  3  oo 

Voltaic  Cell 8vo,  3  oo 

Classen's  Quantitative  Chemical  Analysis  by  Electrolysis.     (Boltwood.).8vo,  3  oo 

*  Collins's  Manual  of  Wireless  Telegraphy i2mo,  i  50 

Morocco,  2  oo 

Crehore  and  Squier's  Polarizing  Photo-chronograph 8ro,  3  oo 

*  Danneel's  Electrochemistry.     (Merriam.) i2mo,  i  25 

Dawson's  "Engineering"  and  Electric  Traction  Pocket-book.  i6mo,  morocco,  5  oo 

10 


Dolezalek's    Theory    of    the    Lead   Accumulator    (Storage    Battery).      (Von 

Ende.) I2mo,  2  50 

Duhem's  Thermodynamics  and  Chemistry.     (Burgess.) 8vo,  4  oo 

Flather's  Dynamometers,  and  the  Measurement  of  Power. xarno,  3  oo 

Gilbert's  De  Magnete.     (Mottelay.) 8vo,  2  50 

Hanchett's  Alternating  Currents  Explained I2mo,  i  oo 

Bering's  Ready  Reference  Tables  (Conversion  Factors) i6mo,  morocco,  2  50 

Holman's  Precision  of  Measurements 8vo,  2  OO 

Telescopic   Mirror-scale  Method,  Adjustments,  and  Tests.  . .  .Large  8vo,  75 

Kinzbrunner's  Testing  of  Continuous-current  Machines ' 8vo,  2  oo 

Landauer's  Spectrum  Analysis.     (Tingle.) 8vo,  3  oo 

Le  Chateliers  High-temperature  Measurements.  (Boudouard — Burgess.)  i2mo,  3  oo 

Lob's  Electrochemistry  of  Organic  Compounds.     (Lorenz.) 8vo,  3  oo 

*  Lyons'?  Treatise  on  Electromagnetic  Phenomena.   Vols.  I.  and  II.  8vo,  each,  6  oo 

*  Michie's  Elements  of  Wave  Motion  Relating  to  Sound  and  Light 8vo,  4  oo 

Niaudefs  Elementary  Treatise  on  Electric  Batteries.     (Fishback.) i2mo,  2  50 

*  Parshall  and  Hobart's  Electric  Machine  Design 4to,  half  morocco,  12  50 

Reagan's  Locomotives:    Simple,  Compound,  and  Electric.      New  Edition. 

Large  12 mo,  3  50 

*  Rosenberg's  Electrical  Engineering.     (Haldane  Gee — Kinzbrunner.).  .  .8vo,  2  oo 

Ryan,  Norris,  and  Hoxie's  Electrical  Machinery.     VoL  1 8vo,  2  50 

Thurston's  Stationary  Steam-engines 8vo,  2  50 

*  Tillman's  Elementary  Lessons  in  Heat 8vo,  i   50 

Tory  and  Pitcher's  Manual  of  Laboratory  Physics Small  8vo,  2  oo 

Ulke's  Modern  Electrolytic  Copper  Refining 8vo,  3  oo 


LAW. 

*  Davis's  Elements  of  Law 8vo,  2  50 

*  Treatise  on  the  Military  Law  of  United  States 8vo,  7  oo 

*  Sheep,  7  So 

*  Dudley's  Military  Law  and  the  Procedure  cf  Courts-martial  .  .  .  .Large  i2mo,  2  50 

Manual  for  Courts-martial i6mo,  morocco,  i  50 

Wait's  Engineering  and  Architectural  Jurisprudence 8vo,  6  oo 

Sheep,  6  50 

Law  of  Operations  Preliminary  to  Construction  in  Engineering  and  Archi- 
tecture  8vo  5  oo 

Sheep,  5  50 

Law  of  Contracts 8vo,  3  oo 

Winthrop's  Abridgment  of  Military  Law I2mo,  2  50 


MANUFACTURES. 

Bernadou's  Smokeless  Powder — Nitro-cellulose  and  Theory  of  the  Cellulose 

Molecule i2mo,  2  50 

Bolland's  Iron  Founder i2mo,  2  50 

The  Iron  Founder,"  Supplement I2mo,  2  50 

Encyclopedia  of  Founding  and  Dictionary  of  Foundry  Terms  Used  in  the 

Practice  of  Moulding i2mo,  3  oo 

*  Claassen's  Beet-sugar  Manufacture.    (Hall  and  Rolfe.) 8vo,  3  oo 

*  Eckel's  Cements,  Limes,  and  Plasters 8vo,  6  oo 

Eissler's  Modern  High  Explosives 8vo,  4  oo 

Effront's  Enzymes  and  their  Applications.     (Prescott.) 8vo,  3  oo 

Fitzgerald's  Boston  Machinist i2mo,  i  oo 

'Ford's  Boiler  Making  for  Boiler  Makers i8mo,  i  oo 

Herrick's  Denatured  or  Industrial  Alcohol 8vo,  400 

Hopkin's  Oil-chemists'  Handbook 8vo,  3  oo 

Keep's  Cast  Iron 8v»,  2  50 

11 


Leach's  The  Inspection  and  Analysis  of  Food  with  Special  Reference  to  State 

Control. ' Large  8vo,  7  50 

*  McKay  and  Larsen's  Principles  and  Practice  of  Butter-making 8vo,  i  50 

Matthews's  The  Textile  Fibres,    yd  Edition,  Rewritten  8vo,  4  oo 

Metcalf's  Steel.     A  Manual  for  Steel-users i2mo,  2  oo 

MetcalfeV  Cost  of  Manufactures — And  the  Administration  of  Workshops. 8vo,  5  oo 

Meyer's  Modern  Locomotive  Construction. 4to,  10  oo 

Morse's  Calculations  used  in  Cane-sugar  Factories i6mo,  morocco,  i  50 

*  Reisig's  Guide  to  Piece-dyeing. 8vo,  25  oo 

Rice's  Concrete-block  Manufacture 8vo,  2  oo 

Sabin's  Industrial  and  Artistic  Technology  of  Paints  and  Varnish 8vo,  3  oo 

Smith's  Press-working  of  Metals 8vo,  3  oo 

Spalding's  Hydraulic  Cement i2mo,  2  oo 

Spencer's  Handbook  for  Chemists  of  Beet-sugar  Houses i6mo  morocco,  3  oo 

Handbook  for  Cane  Sugar  Manufacturers i6mo  morocco,  3  oo 

Taylor  and  Thompson's  Treatise  on  Concrete,  Plain  and  Reinforced 8vo,  5  oo 

Thurston's  Manual  of  Steam-boilers,  their  Designs,  Construction  and  Opera- 
tion  8vo,  5  oo 

*  Walke's  Lectures  on  Explosives 8vo,  4  oo 

Ware's  Beet-sugar  Manufacture  and  Refining.    Vol.1 Small  8vo,  400 

Vol.  II 8vo»  5  oo 

Weaver's  Military  Explosives 8vo,  3  oo 

West's  American  Foundry  Practice i2mo,  2  50 

Moulder's  Text-book i2mo,  2  50 

Wolff's  Windmill  as  a  Prime  Mover 8vo,  3  oo 

Wood's  Rustless  Coatings :   Corrosion  and  Electrolysis  of  Iron  and  Steel.  .8vo,  4  oo 


MATHEMATICS. 

Baker's  Elliptic  Functions.  c  .  „ 8vo,  i  50 

*  Bass's  Elements  of  Differential  Calculus, i2mo,  4  oo 

Briggs's  Elements  of  Plane  Analytic  Geometry 12 mo,  oo 

Compton's  Manual  of  Logarithmic  Computations i2mo  50 

Davis's  Introduction  to  the  Logic  of  Algebra 8vo,  50 

*  Dickson's  College  Algebra Large  i2mOi,  50 

25 
50 
75 
50 

Rational  Geometry i2mo,  50 

*  Johnson's  (J.  B.)  Three-place  Logarithmic  Tables:   Vest-pocket  size. paper,  15 

100  copies  for  5  oo 

*  Mounted  on  heavy  cardboard,  8X  10  inches,  25 

10  copies  for  2  oo 

Johnson's  (W.  W.)  Elementary  Treatise  on  Differential  Calculus.  .Small  8vo,  3  oo 

Elementary  Treatise  on  the  Integral  Calculus Small*8vo,  i  50 

Johnson's  (W.  W.)  Curve  Tracing  in  Cartesian  Co-ordinates, i2mo,  i  oo 

Johnson's  (W.  W.)  Treatise  on  Ordinary  and  PartiaF  Differential  Equations. 

Small  8vo,  3  50 

Johnson's  (W.  W.)  Theory  of  Errors  and  the  Method  of  Least  Squares.  i2mos  i  50 

*  Johnson's  (W.  W.)  Theoretical  Mechanics i2mo,  3  oo 

Laplace's  Philosophical  Essay  on  Probabilities.    (Truscott  and  Emory.) .  i2mo,  2  oo 

*  Ludlow  and  Bass.     Elements  of  Trigonometry  and  Logarithmic  and  Other 

Tables 8vo,  3  oo 

Trigonometry  and  Tables  published  separately Each,  2  oc 

*  Ludlow's  Logarithmic  and  Trigonometric  Tables 8vo  i  oo 

Manning's  Irrational  Numbers  and  their  Representation  by  Sequences  and  Series 

I2mo,  i   25 

12 


*       Introduction  to  the  Theory  of  Algebraic  Equations Large  i2mo, 

Emch's  Introduction  to  Protective  Geometry  and  its  Applications 8vo 

Halsted's  Elements  of  Geometry .8vo, 

Elementary  Synthetic  Geometry. 8vo, 


Mathematical  Monographs.     Edited  by  Mansfield  Merriman  and  Robert 

S.  Woodward Octavo,  each     i  oo 

No.  i.  History  of  Modern  Mathematics,  by  David  Eugene  Smith. 
No.  2.  Synthetic  Projective  Geometry,  by  George  Bruce  Halsted. 
No.  3.  Determinants,  by  Laenas  Gifford  Weld.  No.  4.  Hyper- 
bolic Functions,  by  James  McMahon.  No.  5.  Harmonic  Func- 
tions, by  William  E.  Byerly.  No.  6.  Grassmann's  Space  Analysis, 
by  Edward  W.  Hyde.  No.  7.  Probability  and  Theory  of  Errors, 
by  Robert  S.  Woodward.  No.  8.  Vector  Analysis  and  Quaternions, 
by  Alexander  Macfarlatie.  No.  9.  Differential  Equations,  by 
William  Woolsey  Johnson.  No.  10.  The  Solution  of  Equations, 
by  Mansfield  Merriman.  No.  1 1.  Functions  of  a  Complex  Variable, 
by  Thomas  S.  Fiske. 

Maurer's  Technical  Mechanics 8vo,    4  oo 

Merriman's  Method  of  Least  Squares 8vo,    2  oo 

Rice  and  Johnson's  Elementary  Treatise  on  the  Differential  Calculus. .  Sm.  8vo,    3  oo 

Differential  and  Integral  Calculus.     2  vols.  in  one Small  8vo»    2  50 

*  Veblen  and  Lennes's  Introduction  to  the  Real  Infinitesimal  Analysis  of  One 

Variable 8vo,   2  oo 

Wood's  Elements  of  Co-ordinate  Geometry 8vo,    2  oo 

Trigonometry:  Analytical,  Plane,  and  Spherical 12 mo,     i  oo 


MECHANICAL  ENGINEERING. 

MATERIALS  OF  ENGINEERING,  STEAM-ENGINES  AND  BOILERS. 

Bacon's  Forge  Practice i2mo,  i  50 

Baldwin's  Steam  Heating  for  Buildings I2mo,  2  50 

Barr's  Kinematics  of  Machinery 8vo,  2  50 

*  Bartlett's  Mechanical  Drawing 8vo,  3  oo 

*  "                  "                 "        Abridged  Ed 8vo,  i  50 

Benjamin's  Wrinkles  and  Recipes i2mo,  2  oo 

Carpenter's  Experimental  Engineering 8vo,  6  oo 

Heating  and  Ventilating  Buildings 8vo,  4  oo 

Clerk's  Gas  and  Oil  Engine Small  8vo,  4  oo 

Coolidge's  Manual  of  Drawing 8vo,  paper,  i  oo 

Coolidge  and  Freeman's  Elements  of  General  Drafting  for  Mechanical  En- 
gineers   Oblong  4to,  2  50 

Cromwell's  Treatise  on  Toothed  Gearing i2mo,  i  50 

Treatise  on  Belts  and  Pulleys I2mo,  i  50 

Durley's  Kinematics  of  Machines 8vo,  4  oo 

Flather's  Dynamometers  and  the  Measurement  of  Power 12 mo,  3  oo 

Rope  Driving I2mo,  2  oo 

Gill's  Gas  and  Fuel  Analysis  for  Engineers i2mo,  i  25 

Hall's  Car  Lubrication i2mo,  i  oo 

Bering's  Ready  Reference  Tables  (Conversion  Factors) i6mo,  morocco,  2  50 

Button's  The  Gas  Engine 8vo,  5  oo 

Jamison's  Mechanical  Drawing 8vo,  2  50 

Jones's  Machine  Design: 

Part  I.     Kinematics  of  Machinery 8vo,  i  50 

Part  n.     Form,  Strength,  and  Proportions  of  Parts 8vo,  3  oo 

Kent's  Mechanical  Engineers'  Pocket-book i6mo,  morocco,  5  oo 

Kerr's  Power  and  Power  Transmission 8vo,  2  oo 

Leonard's  Machine  Shop,  Tools,  and  Methods 8vo,  4  oo 

*  Lorenz's  Modern  Refrigerating  Machinery.    (Pope,  Haven,  and  Dean.)  .  .  8vo,  4  oo 
MacCord's  Kinematics;  or,  Practical  Mechanism 8vo,  5  oo 

Mechanical  Drawing 4to,  4  oo 

Velocity  Diagrams. 8vo,  i  50 

13 


MacFarland's  Standard  Reduction  Factors  for  Gases 8vo,  i  50 

Mahan's  Industrial  Drawing.     (Thompson.) 8vo,  3  50 

Poole's  Calorific  Power  of  Fuels.  .  . 8vo,  3  oo 

Reid's  Course  in  Mechanical  Drawing 8vo,  2  oo 

Text-book  of  Mechanical  Drawing  and  Elementary  Machine  Design. 8vo,  3  oo 

Richard's  Compressed  Air i2mo,  i  50 

Robinson's  Principles  of  Mechanism 8vo,  3  oo 

Schwamb  and  Merrill's  Elements  of  Mechanism 8vo,  3  oo 

Smith's  (O.)  Press- working  of  Metals 8vo,  3  oo 

Smith  (A.  W.)  and  Marx's  Machine  Design 8vo,  3  oo 

Thurston's   Treatise    on   Friction  and   Lost   Work   in   Machinery   and   Mill 

Work 8vo,  3  oo 

Animal  as  a  Machine  and  Prime  Motor,  and  the  Laws  of  Energetics .  i2mo,  i  oo 

Tillson's  Complete  Automobile  Instructor i6mo,  i  50 

Morocco,  2  oo 

Warren's  Elements  of  Machine  Construction  and  Drawing 8vo,  7  -50 

Weisbach's    Kinematics    and    the    Power    of    Transmission.     (Herrmann — 

Klein.) 8vo,  5  oo 

Machinery  of  Transmission  and  Governors.     (Herrmann — Klein.).  .8vo,  5  oo 

Wolff's  Windmill  as  a  Prime  Mover 8vo,  3  oo 

Wood's  Turbines 8vo,  2  50 


MATERIALS  OP   ENGINEERING. 

*  Bovey's  Strength  of  Materials  and  Theory  of  Structures 8vo,  7  50 

Burr's  Elasticity  and  Resistance  of  the  Materials  of  Engineering.    6th  Edition. 

Reset 8vo,  7  50 

Church's  Mechanics  of  Engineering 8vo,  6  oo 

*  Greene's  Structural  Mechanics 8vo,  2  50 

Johnson's  Materials  of  Construction 8yo,  6  oo 

Keep's  Cast  Iron 8vo,  2  50 

Lanza's  Applied  Mechanics 8vo,  7  50 

Martens's  Handbook  on  Testing  Materials.     (Henning.) 8vo,  7  50 

Maurer's  Technical  Mechanics 8vo,  4  oo 

Merriman's  Mechanics  of  Materials 8vo,  5  oo 

*  Strength  of  Materials I2mo,  i  oo 

Metcalf 's  Steel.     A  Manual  for  Steel-users I2mo,  2  oo 

Sabin's  Industrial  and  Artistic  Technology  of  Paints  and  Varnish 8vo,  3  oo 

Smith's  Materials  of  Machines I2mo,  i  oo 

Thurston's  Materials  of  Engineering 3  vols.,  8vo,  8  oo 

Part  II.     Iron  and  Steel 8vo,  3  50 

Part  III.     A  Treatise  on  Brasses,  Bronzes,  and  Other  Alloys  and  their 

Constituents 8vo,  2  50 

Wood's  (De  V.)  Treatise  on  the  Resistance  of  Materials  and  an  Appendix  on 

the  Preservation  of  Timber 8vo,  a  oo 

Elements  of  Analytical  Mechanics 8vo,  3  oo 

Wood's  (M.  P.)  Rustless  Coatings:    Corrosion  and  Electrolysis  of  Iron  and 

Steel 8vo,  4  oo 

STEAM-ENGINES  AND  BOILERS. 

Berry's  Temperature-entropy  Diagram i2mo,  i  25 

Carnot's  Reflections  on  the  Motive  Power  of  Heat.     (Thurston.) i2mo,  I  50 

Creighton's  Steam-engine  and  other  Heat-motors — 8vo,  500 

Dawson's  "Engineering"  and  Electric  Traction  Pocket-book.  .  .  .  i6mo,  mor.,  5  oo 

Ford's  Boiler  Making  for  Boiler  Makers i8mo,  i  oo 

Goss's  Locomotive  Sparks 8vo,  2  oo 

Locomotive  Performance 8vo,  5  oo 

Hemenway's  Indicator  Practice  and  Steam-engine  Economy 1210.0,  2  oo 

14 


Button's  Mechanical  Engineering  of  Power  Plants 8vo,  5  oo 

Heat  and  Heat-engines 8vo:  5  oo 

Kent's  Steam  boiler  Economy 8vo,  4  oo 

Kneass's  Practice  and  Theory  of  the  Injector 8vo,  i  50 

MacCord's  Slide-valves 8vo,  2  oo 

Meyer's  Modern  Locomotive  Construction 4to,  10  oo 

Peabody's  Manual  of  the  Steam-engine  Indicator I2mo.  i  50 

Tables  of  the  Properties  of  Saturated  Steam  and  Other  Vapors   8vo,  i  oo 

Thermodynamics  of  the  Steam-engine  and  Other  Heat-engines 8vo,  5  oo 

Valve-gears  for  Steam-engines 8vo,  2  50 

Peabody  and  Miller's  Steam-boilers 8vo,  4  oo 

Pray's  Twenty  Years  with  the  Indicator Large  8vo,  2  50 

Pupin's  Thermodynamics  of  Reversible  Cycles  in  Gases  and  Saturated  Vapors. 

(Osterberg.) i2mo,  i  25 

Reagan's  Locomotives:    Simple,  Compound,  and  Electric.     New  Edition. 

Large  12 mo,  3  50 

Rontgen's  Principles  of  Thermodynamics.     (Du  Bois.) 8vo,  5  oc 

Sinclair's  Locomotive  Engine  Running  and  Management I2mo,  2  oo 

Smart's  Handbook  of  Engineering  Laboratory  Practice i2mo,  2  50 

Snow's  Steam-boiler  Practice 8vo,  3  oo 

Spangler's  Valve-gears 8vo,  2  50 

Notes  on  Thermodynamics i2mo,  i  oo 

Spangler,  Greene,  and  Marshall's  Elements  of  Steam-engineering 8vo,  3  oo 

Thomas's  Steam-turbines 8vo,  3  50 

Thurston's  Handy  Tables 8vo,  i  50 

Manual  of  the  Steam-engine 2  vols.,  8vo,  10  oo 

Part  I.     History,  Structure,  and  Theory 8vo,  6  oo 

Part  II.     Design,  Construction,  and  Operation 8vo,  6  oo 

Handbook  of  Engine  and  Boiler  Trials,  and  the  Use  of  the  Indicator  and 

the  Prony  Brake 8vo,  5  oo 

Stationary  Steam-engines 8vo,  2  50 

Steam-boiler  Explosions  in  Theory  and  in  Practice i2mo,    i  50 

Manual  of  Steam-boilers,  their  Designs,  Construction,  and  Operation .  8vo,  5  oo 

Wehrenfenning's  Analysis  and  Softening  of  Boiler  Feed-water  (Patterson)  8vo,  4  oo 

Weisbach's  Heat,  Steam,  and  Steam-engines.     (Du  Bois.) 8vo,  5  oo 

Whitham's  Steam-engine  Design 8vo,  5  oo 

Wood's  Thermodynamics,  Heat  Motors,  and  Refrigerating  Machines. .  .8vo,  4  oo 


MECHANICS  AND  MACHINERY. 

Barr's  Kinematics  of  Machinery 8vo,  2  50 

*  Bovey's  Strength  of  Materials  and  Theory  of  Structures   8vo,  7  50 

Chase's  The  Art  of  Pattern-making I2mo,  2  50 

Church's  Mechanics  of  Engineering 8vo,  6  oo 

Notes  and  Examples  in  Mechanics 8vo,  2  oo 

Compton's  First  Lessons  in  Metal- working I2mo,  i  50 

Compton  and  De  Groodt's  The  Speed  Lathe I2mo,  i  50 

Cromwell's  Treatise  on  Toothed  Gearing I2mo,  i  50 

Treatise  on  Belts  and  Pulleys I2mo,  i  50 

Dana's  Text-book  of  Elementary  Mechanics  for  Colleges  and  Schools.  .i2mo,  i  50 

Dingey's  Machinery  Pattern  Making i2mo,  2  oo 

Dredge's   Record  of  the  Transportation  Exhibits  Building  of  the   World's 

Columbian  Exposition  of  1893 4to  half  morocco,  5  oo 

Du  Bois's  Elementary  Principles  of  Mechanics : 

Vol.      I.     Kinematics 8vo,  3  50 

VoL    II.     Statics 8vo,  4  oo 

Mechanics  of  Engineering.     Vol.    I Small  4to,  7  50 

VoL  II Small  4to,  10  oo 

Durley's  Kinematics  of  Machines 8vo,  4  oo 

15 


Fitzgerald's  Boston  Machinist i6mo,  i  oo 

Flather*s  Dynamometers,  and  the  Measurement  of  Power i2mo,  3  oo 

Rope  Driving i2mo,  2  oo 

Goss's  Locomotive  Sparks 8vo,  2  oo 

Locomotive  Performance 8vo,  5  oo 

*  Greene's  Structural  Mechanics 8vo,  2  50 

Hall's  Car  Lubrication i2mo,  i  oo 

Holly's  Art  of  Saw  Filing i8mo,  75 

James's  Kinematics  of  a  Point  and  the  Rational  Mechanics  of  a  Particle. 

Small  8vo,  2  oo 

*  Johnson's  (W.  W.)  Theoretical  Mechanics i2mo,  3  oo 

Johnson's  (L.  J.)  Statics  by  Graphic  and  Algebraic  Methods 8vo,  2  oo 

Jones's  Machine  Design: 

Part    I.     Kinematics  of  Machinery 8vo,  i  50 

Part  II.     Form,  Strength,  and  Proportions  of  Parts 8vo,  3  oo 

Kerr's  Power  and  Power  Transmission 8vo,  2  oo 

Lanza's  Applied  Mechanics 8vo,  7  50 

Leonard's  Machine  Shop,  Tools,  and  Methods 8vo,  4  oo 

*  Lorenz's  Modern  Refrigerating  Machinery.     (Pope,  Haven,  and  Dean.). 8vo,  4  oo 
MacCord's  Kinematics;  or,  Practical  Mechanism 8vo,  5  oo 

Velocity  Diagrams .' 8vo,  i  50 

*  Martin's  Text  Book  on  Mechanics,  Vol.  I,  Statics i2mo,  i  25 

Maurer's  Technical  Mechanics 8vo,  4  oo 

Merriman's  Mechanics  of  Materials 8vo,  5  oo 

*  Elements  of  Mechanics i2mo,  i  oo 

*  Michie's  Elements  of  Analytical  Mechanics 8vo,  4  oo 

*  Parshalland  Hobart's  Electric  Machine  Design 4to,  half  morocco,  12  50 

Reagan's  Locomotives :  Simple,  Compound,  and  Electric.     New  Edition. 

Large  i2mo,  3  oo 

Reid's  Course  in  Mechanical  Drawing 8vo,  2  oo 

Text-book  of  Mechanical  Drawing  and  Elementary  Machine  Design. 8vo,  3  oo 

Richards's  Compressed  Air i2mo,  i  50 

Robinson's  Principles  of  Mechanism 8vo,  3  oo 

Ryan,  Norris,  and  Hoxie's  Electrical  Machinery.     Vol.  1 8vo,  2  50 

Sanborn's  Mechanics :  Problems Large  i2mo,  i   50 

Schwamb  and  Merrill's  Elements  of  Mechanism 8vo,  3  oo 

Sinclair's  Locomotive-engine  Running  and  Management I2mo,  2  oo 

Smith's  (O.)  Press-working  of  Metals 8vo,  3  oo 

Smith's  (A.  W.)  Materials  of  Machines i2mo,  i  oo 

Smith  (A.  W.)  and  Marx's  Machine  Design 8vo,  3  oo 

Spangler,  Greene,  and  Marshall's  Elements  of  Steam-engineering 8vo,  3  oo 

Thurston's  Treatise  on  Friction  and  Lost  Work  in    Machinery  and    Mill 

Work 8vo,  3  oo 

Animal  as  a  Machine  and  Prime  Motor,  and  the  Laws  of  Energetics.  i2mo,  i  oo 

Tillson's  Complete  Automobile  Instructor i6mo,  i  50 

Morocco,  2  oo 

Warren's  Elements  of  Machine  Construction  and  Drawing 8vo,  7  50 

Weisbach's  Kinematics  and  Power  of  Transmission.    (Herrmann — Klein.). 8vo,  5  oo 

Machinery  of  Transmission  and  Governors.      (Herrmann — Klein.). 8vo,  5  oo 

Wood's  Elements  of  Analytical  Mechanics 8vo,  3  oo 

Principles  of  Elementary  Mechanics I2mo,  i  25 

Turbines 8vo,  2  50 

The  World's  Columbian  Exposition  of  1893  ... 4to,  i  oo 

MEDICAL. 

De  Fursac's  Manual  of  Psychiatry.     (Rosanoff  and  Collins.) Large  i2mo,  2  50 

Ehrlich's  Collected  Studies  on  Immunity.     (Bolduan.) 8vo,  6  oo 

Hammarsten's  Text-book  on  Physiological  Chemistry.     (Mandel.) 8vo,  4  oo 

16 


Lassar-Cohn's  Practical  Urinary  Analysis.     (Lorenz.) i2mo,  i  oo 

*  Pauli's  Physical  Chemistry  in  the  Service  of  Medicine.     (Fischer.) .  .  .    12100,  i  25 

*  Pozzi-Escot's  The  Toxins  and  Venoms  and  their  Antibodies.     (Cohn.).  i2mo,  i  oo 

Rostoski's  Serum  Diagnosis.     (Bolduan.) I2mo,  i  oo 

Salkowski's  Physiological  and  Pathological  Chemistry.     (Orndorff.) 8vo,  2  50 

*  Satterlee'«*  Outlines  of  Human  Embryology I2mo,  i  25 

Steel's  Treatise  on  the  Diseases  of  the  Dog 8vo,  3  50 

Von  Behring's  Suppression  of  Tuberculosis.     (Bolduan.) i2mo,  i  oo 

Wassermann's  Immune  Sera :  Haemolysis,  Cytotoxins,  and  Precipitins.     (Bol- 
duan.)   i2mo,  cloth,  i  oo 

Woodhull's  Notes  on  Military  Hygiene 1 6mo,  i  50 

*  Personal  Hygiene i2mo,  i  oo 

Wulling's  An  Elementary  Course  in  Inorganic  Pharmaceutical  and  Medical 

Chemistry i2mo,  2  oo 

METALLURGY. 

Egleston's  Metallurgy  of  Silver,  Gold,  and  Mercury: 

Vol.    I.     Silver 8vo,  7  50 

VoL  II.     Gold  and  Mercury 8vo,  7  50 

Goesel's  Minerals  and  Metals:     A  Reference  Book , i6mo,  mor.  3  oo 

*  Iles's  Lead-smelting i2mo,  2  50 

Keep's  Cast  Iron 8vo,  2  50 

Kunhardt's  Practice  of  Ore  Dressing  in  Europe 8vo,  i  50 

Le  Chatelier's  High-temperature  Measurements.  (Boudouard — Burgess. )i2mo,  3  oo 

Metcalf's  Steel.     A  Manual  for  Steel-users 12210,  2  oo 

Miller's  Cyanide  Process i2mo,  i  oo 

Minet's  Production  of  Aluminum  and  its  Industrial  Use.     (Waldo.). ..  .  I2mo,  2  50 

Robine  and  Lenglen's  Cyanide  Industry.     (Le  Clerc.) 8vo,  4  oo 

Smith's  Materials  of  Machines I2mo,  i  oo 

Thurston's  Materials  of  Engineering.     In  Three  Parts 8vo,  8  oo 

Part    II.     Iron  and  SteeL 8vo,  3  50 

Part  HI.     A  Treatise  on  Brasses,  Bronzes,  and  Other  Alloys  and  their 

Constituents 8vo,  2  50 

Ulke's  Modern  Electrolytic  Copper  Refining 8vo,  3  oo 


MINERALOGY. 

Barringer's  Description  of  Minerals  of  Commercial  Value.    Oblong,  morocco,  2  50 

Boyd's  Resources  of  Southwest  Virginia 8vo,  3  oo 

Map  of  Southwest  Virignia Pocket-book  form.  2  oo 

*  Browning's  Introduction  to  the  Rarer  Elements 8vo,  I  50 

Brush's  Manual  of  Determinative  Mineralogy.     (Penfield.) 8vo,  4  oo 

Chester's  Catalogue  of  Minerals^ 8vo,  paper,  i  oo 

Cloth,  i  25 

Dictionary  of  the  Names  of  Minerals 8vo,  3  50 

Dana's  System  of  Mineralogy Large  8vo,  half  leather,  12  50 

First  Appendix  to  Dana's  New  "  System  of  Mineralogy." Large  8vo,  i  oo 

Text-book  of  Mineralogy 8vo,  4  oo 

Minerals  and  How  to  Study  Them 1 2 mo,  i  50 

Catalogue  of  American  Localities  of  Minerals Large  8vo,  i  oo 

Manual  of  Mineralogy  and  Petrography I2mo  2  oo 

Douglas's  Untechnical  Addresses  on  Technical  Subjects i2mo,  i  oo 

Eakle's  Mineral  Tables 8vo,  i  25 

Egleston's  Catalogue  of  Minerals  and  Synonyms 8vo,  a  50 

Goesel's  Minerals  and  Metals :     A  Reference  Book i6mo.mor.  300 

Groth's  Introduction  to  Chemical  Crystallography  (Marshall) 12 mo,  i  25 

17 


Iddings's  Rock  Minerals 8vo,  5  oo 

*  Martin's  Laboratory  Guide  to  Qualitative  Analysis  with  the  Blowpipe,  lamo,  60 
Merrill's  Non-metallic  Minerals:  Their  Occurrence  and  Uses 8vo,  4  oo 

Stones  for  Building  and  Decoration 8vo,  5  oo 

*  Penfield's  Notes  on  Determinative  Mineralogy  and  Record  of  Mineral  Tests. 

8vo,  paper,  50 

*  Richards's  Synopsis  of  Mineral  Characters i2mo,  morocco,  i  25 

*  Ries's  Clays:  Their  Occurrence,  Properties,  and  Uses 8vo,  5  oo 

Rosenbusch's   Microscopical   Physiography   of   the   Rock-making  Minerals. 

(Iddings.) 8vo,  5  oo 

*  Tillman's  Text-book  of  Important  Minerals  and  Rocks 8vo,  2  oo 


MINING. 

Boyd's  Resources  of  Southwest  Virginia 8vo,  3  oo 

Map  of  Southwest  Virginia Pocket-book  form  2  oo 

Douglas's  Untechnical  Addresses  on  Technical  Subjects i2mo;  i  oo 

Eissler's  Modern  High  Explosives 8-3  4   ->o 

Goesel's  Minerals  and  Metals :     A  Reference  Book i6mo,  mor.  3  oo 

Goodyear's  Coal-mines  of  the  Western  Coait  of  the  United  States i2ino,  2  50 

Ihlseng's  Manual  of  Mining 8vo,  5  oo 

*  Iles's  Lead-smelting I2mo,  2  50 

Kunhardt's  Practice  of  Ore  Dressing  in  Europe 8vo,  i  50 

Miller's  Cyanide  Process .  i2mo,  i  oo 

O'Driscoll's  Notes  on  the  Treatment  of  Gold  Ores 8vo,  2  oo 

Robine  and  Lenglen's  Cyanide  Industry.     (Le  Clerc.) 8vo,  4  oo 

*  Walke's  Lectures  on  Explosives 8vo,  4  oo 

Weaver's  Military  Explosives 8vo,  3  oo 

Wilson's  Cyanide  Processes i2mo,  i  50 

Chlorination  Process i2mo,  i  50 

Hydraulic  and  Placer  Mining i2mo,  2  oo 

Treatise  on  Practical  and  Theoretical  Mine  Ventilation I2mo,  i  25 


SANITARY  SCIENCE. 

Bashore's  Sanitation  of  a  Country  House i2mo,  i  oo 

*       Outlines  of  Practical  Sanitation i2mo,  i  25 

Folwell's  Sewerage.     (Designing,  Construction,  and  Maintenance.) 8vo,  3  oo 

Water-supply  Engineering 8vo,  4  oo 

Fowler's  Sewage  Works  Analyses i2mo,  2  oo 

Fuertes's  Water  and  Public  Health i2mo,  i  50 

Water-filtration  Works izmo,  2  50 

Gerhard's  Guide  to  Sanitary  House-inspection 9 i6mo,  i  oo 

Hazen's  Filtration  of  Public  Water-supplies 8vo,  3  oo 

Leach's  The  Inspection  and  Analysis  of  Food  with  Special  Reference  to  State 

Control 8vo,  7  50 

Mason's  Water-supply.  (Considered  principally  from  a  Sanitary  Standpoint)  8vo,  4  oo 


Examination  of  Water.     (Chemical  and  Bacteriological.) I2mo, 

*  Merriman's  Elements  of  Sanitary  Engineering .8vo, 

Ogden's  Sewer  Design i2mo, 

Prescott  and  Winslow's  Elements  of  Water  Bacteriology,  with  Special  Refer- 
ence to  Sanitary  Water  Analysis I2mo, 

*  Price's  Handbook  on  Sanitation i2mo, 

Richards's  Cost  of  Food.     A  Stuiy  in  Dietaries I2mo, 

Cost  of  Living  as  Modified  by  Sanitary  Science i2mo, 

Cost  of  Shelter i2mo, 

18 


Richards   and  Woodman's  Air    Water,  and  Food  from  a  Sanitary  Stand- 
point  8vo,  2  oo 

*  Richards  and  Williams's  The  Dietary  Computer 8vo,  i  50 

Rideal's  S  wage  and  Bacterial  Purification  of  Sewage 8vo,  4  oo 

Disinfection  and  the  Preservation  of  Food 8vo,  400 

Turneaure  and  Russell's  Public  Water-supplies 8vo,  5  oo 

Von  Behring's  Suppression  of  Tuberculosis.     (Bolduan.) i2mo,  i  oo 

Whipple's  Microscopy  of  Drinking-water 8vo,  3  So 

Winton's  Microscopy  of  Vegetable  Foods 8vo,  7  50 

Woodhull's  Notes  on  Military  Hygiene i6mo,  i  50 

*  Personal  Hygiene i2mo,  i  oo 


MISCELLANEOUS. 

Emmons's  Geological  Guide-book  of  the  Rocky  Mountain  Excursion  of  the 

International  Congress  of  Geologists Large  Svo,  i  50 

Ferrel's  Popular  Treatise  on  the  Winds Svo,  4  oo 

Gannett's  Statistical  Abstract  of  the  World 241110  75 

Haines's  American  Railway  Management I2mo,  2  50 

Ricketts's  History  of  Rensselaer  Polytechnic  Institute,  1824-1894.. Small  Svo,  3  oo 

Rother ham's  Emphasized  New  Testament c Large  Svo,  2  oc 

The  World's  Columbian  Exposition  of  1893 4to,  i  oc 

Winslow's  Elements  of  Applied  Microscopy i2mo.  i  sc 


HEBREW  AND  CHALDEE  TEXT-BOOKS. 

Green's  Elementary  Hebrew  Grammar I2mo,  i  25 

Hebrew  Chrestomathy Svo,  2  oo 

Gesenius's  Hebrew  and  Chaldee  Lexicon  to  the  Old  Testament  Scriptures. 

(Tregelles.) Small  4to,  half  morocco,  5  oo 

Letteris's  Hebrew  Bible Svo,  2  25 

19 


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